Autism and Lactate/Lactic Acid

Greetings Earthlings! 🙂

This week I’d like to discuss an interesting biomarker that is elevated in people with autism- lactate.

So what exactly is lactate?

Lactate, also known as lactic acid, is a bi-product of normal energy metabolism in the body. You might have heard of it in relation to exercise as lactic acid builds up in the muscles when oxygen is low leading to that burning sensation we sometimes experience. Normally the body produces energy by breaking down glucose in the mitochondria in our cells using oxygen (aerobic respiration), but when oxygen is low, glucose is broken down without oxygen (anaerobic respiration). This happens separately in the cytosol, the liquid inside of cells, where energy is produced along with the waste product lactic acid.

But what does all this have to do with autism?

Mitochondrial dysfunction is thought to be one of the possible causes of autism spectrum disorders as the nervous system is the most commonly impacted system. Recent studies supporting this theory have shown that lactate levels are elevated in autists which are thought to have an influence on behavioural issues. When mitochondria cannot perform efficiently to produce energy in autism, there are two potential alternatives- the cell may compensate using the anaerobic pathway described above, or by using something called the Warburg effect. The Warburg effect describes when energy is produced outside the mitochondria in the cytosol despite the presence of normal oxygen levels where lactate is produced as a bi-product. Research suggests that the canonical WNT/β-catenin pathway, which is involved in the regulation of the enzymes that control metabolism, is abnormally activated in autism leading to energy production via the Warburg effect. Interestingly, lactate is also elevated in lots of other disorders that can be co-morbid with autism such as bipolar disorder, depression, ADHD and gastrointestinal disorders.

Who knew that the pesky burn you feel during exercise could have such an influence on our brain chemistry!

Hope you enjoyed this post dear Earthlings!

Have a lovely weekend! 🙂

Aoife

March 3, 2023 0

Autism and Dyslexia

Greetings Earthlings! 🙂

This week I’d like to take a look at another neurological condition that can be co-morbid with autism- dyslexia.

First things first, what is dyslexia?

Dyslexia can be described as a specific type of learning disability that impacts a persons reading, writing and spelling abilities. Impacting approximately 10% of the population, dyslexia ranges from mild to severe characterized by cognitive difficulties with processing phonetics, working memory and speed of long term memory retrieval. Like autism, the exact neurological causes and mechanisms are unclear, but as dyslexia can run in families, genetic factors are largely thought to contribute.

So how is it linked to autism?

The link between autism and dyslexia has not been scientifically established, but there are some commonalities. Interestingly, dyslexia overlaps with many autistic co-morbidities such as ADHD, dysgraphia, dyspraxia (an estimated 52-53% of dyslexics are also dyspraxic), and auditory processing disorders, which would suggest that these conditions likely operate through similar neurological mechanisms and pathways.

Scientists have found it difficult to establish a direct genetic link between the two conditions, however, recent research may implicate gene deletions in CNTNAP5 (a gene involved in connecting neurons) and DOCK4 (a gene that regulates junctions between cells) in both dyslexia and autism. In addition to this, a 2015 study found that declarative memory (the type of memory that can be “declared” like names, facts, figures etc.) can be used to develop coping mechanisms for both autism and dyslexia, suggesting that perhaps there may be overlap in the brain regions associated with this type of memory formation. Other studies exploring the neural mechanisms of dyslexia indicate structural changes in such regions as the frontal lobe (memory and problem solving), cerebellum (the motor centre) and corpus callosum (the bundle of nerves that splits and connects the left and right hemispheres of the brain)- all areas that have also shown structural changes in studies of the autistic brain.

Most recently, a 2021 study exploring the co-occurrence of dyslexia and other neurodevelopmental disorders reported that many dyslexic patients in their dataset also had issues with sensory processing and other ASD traits, but concluded that the links between the two conditions are complex and hard to underpin, especially given that some autists are hyperlexic (guilty!) rather than dyslexic.

Whilst there is no definitive scientific link, the overlap cannot be denied.

Hope you enjoyed this post dear Earthlings! 🙂

Have a lovely weekend!

Aoife

July 8, 2022 3

Autism and Brain Zaps

Greetings Earthlings! 🙂

Leading on from my previous post about autism and anxiety, this week I’d like to talk about the phenomenon of brain zaps which autists may experience.

So what exactly are brain zaps?

Brain zaps (also know as brain shakes/shocks/shivers/flips) are a poorly understood phenomenon where it feels as though the brain is undergoing an electrical shock or a shaking/shivering/vibrating sensation. I personally have experienced these from time to time as a vibrating sensation in my brain, where it feels like your brain is literally shaking in your skull. Others report that it feels like a zap has gone off in their head and they can hear a hissing or a ringing sound in their ears. In some cases people experience bursts of light and can feel faint and disorientated afterwards. They are not harmful to the brain but they can be distracting and uncomfortable, especially for autists who are already sensitive to sensory stimuli.

So what causes them?

Like many neurological sensations, they are somewhat of a mystery, but they generally tend to occur in response to withdrawal or missed doses of certain drugs such as anti-depressants, ecstasy and MDMA, and medications for anxiety and ADHD – many of which are prescribed for co-morbid mental health conditions in autists. As these drugs alter levels of key calming inhibitory neurotransmitters such as serotonin and GABA (levels which are naturally dysregulated in the autistic brain), it is thought that low levels of these neurotransmitters may cause over-excitement in the brain, leading to abnormal firing between the neurons causing localized minor seizures i.e. brain zaps.

Don’t be alarmed by the term seizure here- this theory has not yet been confirmed and there is no evidence that brain zaps have a negative impact on our health.

On the other hand, brain zaps can also occur in response to high stress and anxiety. When you experience chronic stress, the brain is hyperstimulated as your worries swirl round and around in your restless mind. Completely overworked and overexcited from stress, your neurotransmitter levels fluctuate causing lower levels of calming GABA and higher levels of glutamate- the primary excitatory neurotransmitter. Such changes may over-excite the brain resulting in a localised seizure/brain zap as described above. Autists may be particularly susceptible to brain zaps in this manner as we experience higher levels of biological stress than our neurotypical peers, not to mention that our neurons are naturally hyper-connected, our neurotransmitters dysregulated and our brains hyperstimulated as a result.

Interestingly, a recent study has suggested that lateral eye movement may be a triggering factor for brain zaps. This is particularly intriguing for autists as evidence suggests that we process most visual information in our periphery, so our natural inclination to avoid direct eye contact could trigger brain zaps.

There are no treatments for brain zaps, but while they may not be the most pleasant sensation, they are generally nothing to be worried about and can be mitigated with proper management of stress and your prescribed medications.

Hope you enjoyed this post dear Earthlings! 🙂

Have a lovely weekend!

Aoife

June 6, 2022 0

Autism and Asthma

Greetings Earthlings! 😀

Having just been officially diagnosed with asthma this week (after 23 years of uming and ahing about whether to diagnose as it’s been mild thusfar), I decided to do some investigating to see if there are any links between ASD’s and asthma.

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Did you know, that autists are 35% more likely to suffer from asthma than the general population?

Seemingly random, but true!

So what exactly is happening in the lungs of asthmatics?

Asthma is a chronic inflammatory disease of the airways in the lungs. Inflammation in the airways in response to triggers (such as allergens, cold air, tobacco smoke etc.) causes the airways to narrow and spasm, resulting in bouts of wheezing and shortness of breath- which I’m ironically experiencing as I write this *drags deeply on inhaler*.

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But how exactly are asthma and ASD’s intertwined?

The exact cause of asthma, like autism remains unknown, however, it’s inflammatory nature may reveal it’s links to autism. A recent study suggests that there is a connection between inflammation and ASD’s. Post mortem examination of the brains of autists show that there are increased levels of the pro-inflammatory cytokine (a substance secreted by the immune system) IL-18 in the amygdala and the dorsolateral prefrontal cortex of the brain- areas where alterations are often linked to autism. Perhaps these increased inflammatory markers may predispose autists to the development of asthma. Moreover, research has shown that there is genetic overlap between asthma genes and multiple mental health disorders such as anxiety, ADHD and major depressive disorder (MDD) that are often co-morbid with autism, which could suggest a common genetic pathway for both asthma and autism.

In addition to the link between asthma and autism, recent research suggests that having a parent with an asthma diagnosis may slightly increase the risk of autism development. However, there are conflicting studies as to whether or not the use of asthma medications during pregnancy may increase this risk (although the most recent of these studies supports their use).

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Hope you enjoyed this post dear Earthlings! 😀

Have a lovely weekend!

Aoife

December 6, 2019 1

Research News Update July 2018

Greetings Earthlings! 🙂

The world of research is fast paced- every day new studies are published telling us new and exciting things about the human body. As the scientific community has yet to pinpoint the exact underlying mechanisms involved in autism, the wheel of research is constantly churning out new evidence to provide us with a better picture of the autistic brain.

Since my previous post about the neuroscience of autism, there have been several new and exciting insights into the physiology of the autistic brain, so I’ve decided to give you a brief summary of the research! 🙂

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Folding in the Brain

In recent weeks a study has emerged that suggest that symptoms of autism may be attributed to excessive folding in the brain.

No- I’m not talking origami, but the formulation of the squiggly ridges or ‘folds’ that make up the brain (by a process known as gyrification) as you can see in the gif below:

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Brain tissue folds to allow for a greater surface area for cognitive functioning within the cramped confines of the skull- like a bar of chocolate melts quicker when you break the pieces up, so too does the folded brain work more efficiently than if the surface were smooth.

Recent research shows that autists brains may not fold in the same way as their neurotypical peers. Some regions of the brain, such as those associated with facial recognition are smoother in autists, whereas other areas such as the temporal (sensory processing) and frontal lobes (memory and attention) show signs of exaggerated folding. Excessive folding in these areas could explain sensory sensitivities in autists, in addition to variations in memory and attention deficits. On the other hand, decreased folding in the occipital lobe may explain why autists struggle with facial reading and processing 🙂

Brain Shape

In addition to folding, recent research has focused on the cerebellum (meaning little brain in Latin) which contains roughly 80% of the neurons of the brain whilst only taking up 10% of it’s total volume! Thought to be associated with implicit learning (learning without awareness like learning to ride a bike or to swim), sensory function and cognitive function, 3D analysis of MRI data suggests that the shape and structure of the cerebellum may be different in autism. It appears that in some autists the cerebellum is flatter on the right side (the flatter the tissue, the lower the efficiency of the brain), but in autists with higher functioning social skills the structure is closer to that of a neurotypical individual- which may explain some of the communication difficulties associated with autism as the right side of the cerebellum is associated with language processing.

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Abnormal Brain Connections

MRI scans of preschoolers with autism have provided more evidence that the autistic brain is abnormally connected. In this study it appears that a number of brain networks connecting different areas of the brain show significant differences from neurotypicals. A number of components of the basal ganglia network in particular were altered in autism (which plays an important role in behaviour). Differences were also found in the para-limbic network which is also involved in behaviour in addition to emotional processing, motivation and self-control.

This may indicate the use of MRI scans to obtain faster autism diagnoses in the future, but it’s still very much early days 🙂

There we have it now dear Earthlings, hope you hadn’t missed me too much while I was away.

Enjoy the weekend everyone! 🙂

brain

Aoife

July 27, 2018 0

Autism and Echolalia

Greetings Earthlings! 🙂

This week we’re going to talk about something that effects approximately 75% of autists- Echolalia.

I know, I know, it’s a mouthful- but echolalia is actually quite simple:

Echolalia is the meaningless repetition of noises, words or phrases immediately after their occurrence (although sometimes this can be delayed).

Derived from Greek echo, “to repeat,” and laliá, meaning “talk” or “speech,” Echolalia is an automatic and unintentional behaviour. In most cases Echolalia is used in an attempt to communicate, practice or even learn language. In fact, Echolalia is part of normal development- every child experiences Echolalia when they learn a spoken language.

However, whilst “normal”, this behaviour can persist for longer in autists.

But why might this be?

Psychologically speaking, Echolalia is considered by some to simply be a repetitive or self-stimulatory behaviour in autists (as some experience this behaviour only when they are stressed), however, the general school of thought is that it is a communicative behaviour. Imitative behaviour is an essential part of social learning. As autists struggle so much socially, this imitative behaviour can act as a tool to help improve their social skills.

I’ve certainly exhibited such imitative behaviour during my formative years. For example, I somehow got it into my head that in my final year of primary school I needed to practice my swearing so that I would better be able to fit in when I made the jump to secondary school! 😬🙈 Wasn’t especially successful- sure I could swear like a sailor, buuuuuut it didn’t do much to improve my social skills or status (but I suppose I sounded a little less like a walking thesaurus for a change! 😛 ).

On the biological side of things, much of the physiology of Echolalia remains to be explored, however, one study indicates that the ITGB3 gene (which carries the information for β3 integrin- a cell membrane protein that will interact with other proteins to trigger a number of biochemical reactions in our cells) seems to link autism and echolalia.

There we have it now Earthlings I hope you enjoyed this post! 🙂

Have a lovely weekend everyone! 😀

Aoife

June 22, 2018 5

Autism and Memory

Greetings Earthlings! 🙂

In today’s post we’re going to explore the concept of memory and autism.

When we think of autism and memory, we often picture the ‘Rain Man‘ stereotype- an individual with superb, photographic memory.

Whilst this is a stereotypical view of autism, stereotypes often are based on fact. It is indeed true that many autists possess impeccable and often eidetic memories (although the scientific jury is still out as to whether or not true eidetic memories really exist).

Just check out this autstic artists sketch drawn entirely from memory! 😲

However, the opposite is also true in that many individuals with autism equally possess a number of memory deficits such as difficulties with short term and working memory (a part of the short term memory that temporarily stores information for processing-e.g decision making, reasoning and behavior). As a result of this, children with autism often have poorer memory for more complicated information.

My own memory has always been kind of strange- I fall somewhere between having a normal memory and an eidetic one (I definitely don’t have a full eidetic memory- school would have been a lot easier if I had! 😛 )

bitmoji792226925 Whilst I can’t recite the entire works of JK Rowling word for word, my brain does however, tend to randomly churn out eidetic memories every now and again (known as sporadic eidetic memory). I sporadically come out with full eidetic memories recalling such minuscule details as clothes, smells, songs, haircuts etc. My memories are so detailed that I once when recounting the previous night’s episode of Desperate Housewives to my Physical Therapist went so far as to mention the likely flavour of smoothie that the ladies of Wisteria Lane were drinking as they gossiped! 😂😬

I’ve unwittingly been dubbed the “family historian” as a result 😛

But what has the science to say about memory and autism?

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The research is conflicting. Scientists have had great difficulty in obtaining consistent results across memory studies- they are as diverse as the spectrum itself!

However, there are a couple of areas in which scientists seem to agree:

Visual memory is thought to be a particular strength in autists due to increased activity in visual areas of the autistic brain, resulting in enhanced perceptual processing (and eidetic memory formation)
Deficits in working memory may arise from alterations in the brain networks involved in working memory such as the amygdaloid complex and the medial temporal lobe (MTL) affecting their ability to encode and process information

Fun Fact: The regions of the brain involved in declarative memory (memory of facts and events) are thought to compensate for social deficits in autism, becoming activated in social situations to allow autists to mask (for example using formulaic speech i.e. learned phrases)

That’s all for this week dear Earthlings- I hope this post was ‘memorable’ 😉

Enjoy the weekend! 😀

Aoife

June 8, 2018 5

Broad Autism Phenotype (BAP)

Greetings Earthlings! 🙂

Today we’re going to discuss a type of autism that lies just outside the spectrum- the broad or broader autism phenotype (BAP).

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What on earth is that when it’s at home?!

BAP is a term used to describe a wider range of individuals just beyond the spectrum who have difficulties with language, personality, and exhibit a number of social and behavioural traits at a higher level than the average neurotypical, but not so high as to be diagnosed with autism.

In other words, this means that you have “a touch of autism” or “not quite autism (NQA)”. The individual has a high number of mild traits, but not enough to interfere with daily life.

So what do we know about BAP?

Relatively little- it doesn’t even have a Wikipedia page!

This intermediate description is most commonly associated with family members (parents, siblings, and other extended family members) of those with ASD diagnoses (14–23%), but it can also be found in the general population as well (5–9%).

Interestingly, evidence of an intermediate autism phenotype has existed since the late 1970’s (the term itself was coined in 1994), but it is only in recent years, with the expansion of the spectrum, that it has become a source of research interest for scientists seeking to understand the range of ASD’s that lie beneath the spectrum rainbow.

Broader autism phenotype

Much of the research in this area involves using the BAP to better understand autism- in particular it’s severity and genetics. By analyzing autism traits in families through the prism of BAP for example, researchers may be better able to identify the specific genes which underpin ASDs, paving the way for better therapies for autists.

Apologies for the shortness of this post dear Earthlings, but there is sadly very little information out there about BAP. Perhaps in the future there may be new research that will shed greater light on this subject 🙂

Have a good weekend everyone! 🙂

Aoife

February 23, 2018 1

Autism and Smell

Greetings Earthlings! 🙂

As I mentioned in last weeks post on taste sensitivity, this week we’re going to discuss sensitivity to smell in autism.

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As with other senses we have discussed, autists can be either hyposensitive or hypersensitive to odours. One autist may enter a malodorous environment without noticing anything amiss, another autist may wretch, or worse!

As a child, my nose was particularly sensitive to my environment (although judging by how I could taste the beer my friends were drinking yesterday evening from the fumes alone, this may still be the case on occasion 😛 ). Bad smells were especially trying- the smell of salads, fish, cigarette smoke, incense, even something so simple as a bag of popcorn could easily turn my stomach.

But it wasn’t all bad- this sensitivity comes with a heightened appreciation for pleasant smells too 🙂

Baking, chocolate, nice perfumes, the outdoors, the smell of metal (don’t ask me why I love this one so much- must be something to do with my taste in music! 😛 😉 )- in fact, such smells are not only a sensory sensation, but can also be used to help calm an autist.

As easily as an unpleasant smell could unsettle me, the right smell could calm me back down again as a child. I always kept a teddy or a blanket near at hand that I could smell to help soothe and calm me and to lull me off to sleep- I couldn’t sleep without one particular teddy until I was 16!

^^^^My teddy was a lot more raggedy than this…😬

So why does smell affect autists so much?

Interestingly, some studies indicate that there are no differences in sensitivity to smell between autists and their neurotypical peers, however, much research points to the cortex of the brain. This region is heavily involved in smell processing, and yep, you guessed it- the autistic brain shows signs of dysfunction in this region. In fact, the pre-frontal cortex shows signs of overgrowth and excessive linkage in the neurons (just like an overloaded plug), so no wonder sensory perception is altered in autists! This region is also associated with the formation and retrieval of long term memories, which could also explain why smells are often tied to memory recall in autists (which I will explore in more detail at a later stage 🙂 ).

One study also shows that autists may not inhale smells in the same way to their neurotypical peers. Evidence suggests that autists inhale deeply and intensely for both pleasant and unpleasant smells, whereas neurotypicals will tentatively sniff in the presence of an offending odour, which could further explain differences in scent processing.

In addition to this, research suggests that alterations in smell can influence social behaviours. A recent study in fact suggest that autists cannot smell fear and that there is a reversal in their response to fear. In this study, a group of autists were calm when presented with a sample of sweat from a skydiver, whereas their neurotypical peers exhibited classic signs of fear. In contrast, their fear levels increased when presented with the sweat sample from a calm individual!

In other words, an autists social behaviour may be affected by an inability to interpret social cues carried in odours- the mind boggles!

So there we have it dear Earthlings- hope this post didn’t ‘stink’ too badly 😛 😉

Enjoy the weekend everyone! 🙂

Aoife

February 16, 2018 2

Autism and Taste

Greetings Earthlings! 🙂

As we have discussed in previous posts (such as sensory issues, light sensitivity and sound sensitivity), people with autism are highly sensitive on a sensory level, so naturally, taste is no exception.

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Many autists have highly sensitive taste buds wherein we find a number of flavours and foods too strong and overpowering to tolerate. This sensitivity to tastes can make life very difficult when it comes to taking medicines, food selection (which we will discuss in greater detail at a later stage) and maintaining a somewhat neutral expression when put in awkward public tasting scenarios (perhaps one of my biggest personal challenges 😛 ).

On the other hand, some autists can in fact be hyposensitive to taste, often preferring foods with stronger flavours

So what’s causing these alterations in tongue sensitivity?

The research into this aspect of autism is currently quite limited, however, some neurological studies indirectly suggest that there is evidence of taste dysfunction in autism.

Many studies have shown evidence of brainstem dysfunction in the neurodiverse brain such as hypoplasia, or under development of the facial nerve nucleus (a collection of neurons in the brainstem that innervate the face). This nerve network carries taste information from the tongue and relays it to the brain. Any dysfunction or damage to this pathway can affect a persons ability to detect tastes.

Furthermore, the ability to identify tastes and flavour perception is controlled by a complex nerve network involving several different brain regions such as the thalamus, insula/operculum, the orbitofrontal cortex (OFC) and our old friend the amygdala. Many of these regions have been implicated in autism, suggesting that dysfunctions in these regions may influence an autists taste buds.

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Recent evidence also suggests that autists may be more sensitive to bitter tastes due to genetic mutations in the TAS2R38 taste receptor. Alterations in the TAS2R38 gene can cause autists to perceive bitter tastes differently to their neurotypical peers which could explain why our taste buds are so sensitive (and why alcohol makes me gag 😛 )

Finally, an increased sensitivity to smell also feeds into these alterations in taste which I will examine next week 🙂

Until next time Earthlings! 🙂

Aoife

February 9, 2018 2