Welcome to From the Spectrum Podcast. This is a podcast about autism. It is my
goal to explain what is autism. I intend to use a mixture of scientific
literature, personal experience, and opinion. With opinion I will explain why
I feel the way I do and give examples. I will provide links to various
references for each episode. For each episode we will discuss various aspects
of autism. For today's episode we will discuss biological aspects implicating
the excitation and inhibition balance. The EI balance is a worthy discussion
with autism and a lengthy discussion. Today's episode is part 2 of a two-part
series covering the EI balance. Notice not all of the topics covered are a
cause of all the cases of autism. Autism is a genetic patchwork. It is not one
gene and not all gene implications reach autistics in the same manner. The
cause of all autistic phenotypes are unknown. I want to warn you, you need to
know some literature and even some literature I have shared on autism are
attempts to create pharmacological help. This has concerns. This has concerns
because of our medical paradigm which likes and maybe even prefers
prescriptions as the first line, as something that gets lots of financial
backing and it isn't hard to know why. I want you to understand autism and I want
you to make informed decisions. For today's episode we will cover metabolic
demands, glutamate and GABA, some neuromodulators like serotonin, dopamine,
epinephrine and nor epinephrine, remember that's adrenaline and acetylcholine. Also
N-methyl deaspartate which is NMDA and AMPA. Remember feel free to look up the
nomenclature to AMPA. We will also discuss a couple of brain networks, the
thalamocortical and the medial prefrontal cortex. Also learning and memory,
remember neuroplasticity. Remember this is essentially occurring in the
background as certain cells are firing and making us more of what we are. This is
the basis of who we are. So the excitation inhibition creates a noisy and
metabolic demanding condition. This can create crash or burnout or avoidance.
This could mean the interaction if chosen or when it cannot be avoided is very
demanding or more accurately it could be or it likely will be demanding. This
explains a lot of criteria A. That alone helps explain a lot about autism.
Metabolic demands keeping up with the demanding outside world, paying attention
and making sense of everything and consider that rate of information we
previously discussed, that fire hose of information. We keep track at least our
brain or body does of our metabolic account. We meaning our brains, we
meaning people. Lisa Feldman Barrett compares it to a bank account. Do I have
enough resources to cover whatever task or environmental demand I am navigating?
Or will that task demand cause me a metabolic deficit? Will I overdraw my
metabolic account? My metabolic resources. Excitation is demanding. It works the
sympathetic nervous system, the get up and go side. Inhibition is calming and
quieting. Remember it shuts systems down. It works the parasympathetic side, the
inactivating and relaxing side. Remember glutamate is excitation, GABA is
inhibition. In autism, glutamate is more behavioral symptoms and GABA is more
sensory processing and not limited to just those. Criteria A and B are
downstream of these conditions, meaning a result of or a response to. Because of the
excitation inhibition, we get criteria A and B. Possibly a sequela of the
abnormal brain development. Whatever that looks like for the autistic. NMDA, N
methyl D aspartate. NMDA increases signaling between cells. It excites
cells and connections. It is common. NMDA and AMPA have spatial relationships,
meaning they are often close and work alongside each other for the overall go
and intentions of the cell. Which in this case is excitation or activation. NMDA
and AMPA are excitation receptors for glutamate. Dopamine modulates glutamate
release. Remember dopamine has many functions in the human body. Much more
than most know. Here dopamine starts glutamate. Remember to activate and
glutamate carries out several physiological responses in the nervous
system. Symnaptic plasticity is the basis for learning and memory. Remember
essentially this is neuroplasticity. Becoming who we are. Our old friend the
striatum is a region of interest. Remember the striatum and the ventral
striatum is the nucleus of compass. Think of it as a subdivision within a
larger community. The striatum is where motor movements essentially begin and
decision-making. Go directed task, social behaviors, habit and emotions. So once
again we uncovered many bases of autism symptomology. The data on AMPA shows
social implications. Further the data show AMPA dysfunction does not affect
repetitive behaviors and cognitive deficits. In autism AMPA can have hyper
or hypo excitatory transmission. Again hinting on the spectrum and the ability
to navigate certain environments differently. For repetitive type symptoms
this looks to be more NMDA. Additionally and on the theme of neuroplasticity
and or a synaptic plasticity. AMPA receptors are crucial for memory. When BDNF
from our previous episode, NMDA and or AMPA are inhibited, massive impairments
occur. The EI imbalance occurs. Remember that is not limited to autism but
certainly a factor in autism. Neuromodulators. Okay we discussed aromatic
amino acids, tryptophan and tyrosine. These two special proteins account for
the synthesis of most neuromodulators. Remember neuromodulators are slightly
more complex than neurotransmitters even though they are essentially the same.
Neuromodulators are serotonin, dopamine, epinephrine and nor epinephrine and
acetylcholine. These are crucial for the functioning of the human body and the
nervous system. With that deficiencies of these are not, are not necessarily
related to autism. Directly. However remember dopamine in the human body is
much, much more than the wanting, the pursuit, the craving we think of and
serotonin is likely the most studied neuromodulator within this class for
autism. Dating back to the 1960s. Remember the 16p11.2 discussion. Serotonin is
about having and helps determine active coping versus passive coping. In other
words how you respond to events perceived as unwanted or aversive. A subregion of
the thalamus is involved here too. The lateral habinula and lots is going on
here with avoidance, feelings, social behaviors so more of that and adapting
sensory integration and perhaps even more larger system integration. So
consider that on the superpower to super deficit spectrum. Mainly with
neuromodulators each modulator kind of owns a piece of brain real estate. For
serotonin remember having is the raffae an area in the brainstem. Dopamine is the
substantia nigra and also melanin is huge here from a previous discussion and in
the ventral tegmental area epinephrine and nor epinephrine remember brain
adrenaline is the locus ceruleus and acetylcholine used for focus it modulates
focus is the basal for brain or specifically the subdivision nucleus
basalis. Remember these things activate and inactivate whole systems or regions
of the nervous system. The topic with autism is those modulators and those
specific regions implicate the cell activity and subsequent glutamate and
GABA and the cortical and sub cortical communication because in large part
autism has the implications and connection possibly through myelin or
axonal impairment, synaptic impairments, any of the developmental regions of
interest that we have discussed. The list and discussion on these incredible
neuromodulators is no way near exhaustive. One thing to note and I did not
specifically search for any data but acetylcholine and muscle movement is
this implicated in autism. I don't know but acetylcholine controls muscles and
the reason why I wonder is of the motor movement symptoms with autism. Lastly the
nicotinetic receptors for acetylcholine are not only excitable but considered a
rapid excitation. It's like giving the car extra gas for acceleration.
Acetylcholine is used for our focus, how and where we will use our metabolic
energy. A crucial area in the brain is the medial prefrontal cortex. The medial
prefrontal helps determine how we feel, our mood in real time or during thought,
or planning. Remember we run models of how we will feel and do as we navigate
the world. All of us do, autistics or not. A buzzword in neuroscience is the
default mode network. Briefly because it will be too much for this episode, the
default mode network is a state of being during periods of no task demands. Well
for autistics we have plenty of tasks. Remember the criteria B. We have tasks and
interest. In other words how others experience this state of a lack of
demands. Autistics being isolated to ourselves. We can thrive in this time and
because of neuroplasticity we can prefer this time. The medial prefrontal
cortex uses glutamate and GABA. Of course especially GABA to quiet the body during
planning. Recently it was found by Nolan Williams. The medial prefrontal cortex
sends signals down to the heart and slows the heart down during those
excitable states, during those unwanted states. Anyway high excitation
impairs information processing. In the medial prefrontal cortex especially
social and cognition. GABA sets corresponding thalamocortical circuits.
Here we are talking about those connections and communications. Cells
traveling and activating and inactivating systems. Remember the thalamus is the
hotspot. A hotspot for the senses and sensory processing. The thalamocortical
is the pass from the thalamus to the cortex. It relayes sensory information and
integrates it with appropriate systems. The medial generates social responses,
behavioral flexibility and ambition of responses and attention and emotion.
Remember two things. Don't consider a singular area to be the only place or
thing responsible. Such as attention or emotion is the medial prefrontal. Nothing
in the human body is singular. Two, the medial prefrontal is very
metabolically demanding. It requires a lot of energy and resources. Remember the
CNT NAP2 discussion. A lack of inhibitory responses complicates socialness and
cognitive flexibility. And you can see this with traits of autism. So right
there that's criteria A and B. We just highlighted key components for each
criteria. In the background the foot soldiers of our brain and nervous
system are those neuromodulators such as serotonin. Remember vast for socialness
and active versus passive coping. And dopamine. Where do we want to provide
energy for our pursuits? Sapolsky says dopamine isn't about the pursuit of
happiness. Dopamine is about the happiness of pursuit. And I challenge you to
explain it any better than that on the cellular level of wanting. Dopamine is
wanting. Serotonin is having. This is a healthy balance. Many things in our
biology can be seen on that seesaw. Remember the seesaw with the glutamate
and GABA. And remember as a response to those neuromodulators glutamate and GABA
are also constantly running in the background. All the while neuroplasticity
is occurring. Strengthening of connections at the synaptic level.
Strengthening those synaptic connections. A crucial consideration especially with
autism. A crucial consideration is more sensory input equals faster firing rates
of the items discussed today. That is a normal EI balance. So in other words to
repeat more sensory input equals faster firing rates of the items discussed
today. This is a condition with a normal EI balance. Now imagine when the
EI is imbalanced. Imagine the firing rates now. Today's discussion and the
previous episode highlights opportunities for superpowers and
super deficits. Now you, you don't get to determine this. It is the responsibility
of others to help people with autism to find their superpowers. Nobody controls
the rate of information autistics have. Nobody controls what superpowers each
autistic will receive. In addition it is also up to the autistic when possible to
find their superpowers. However delay public and the surrounding people cannot
and should not limit people with autism. One of the best things you can do for
autism is just delete everything you know about autism and then relearn it.
Learn what autism is actually and whenever I say delete just go ahead and
wipe it out. But don't worry our memory in the human brain is often like the
memory on our computer. You're not actually going to delete it completely out. It
will still be there in the background. You can still retrieve it. My point is
don't limit your capacity to think. Don't be offended by people asking you to
think differently. To expand your critical thinking especially on this autism
phenomena. Don't try to change an autistic person because they are
different than you or different than others. Don't let that offend your
beliefs and capacity to apply critical thinking in life. If you are listening
and enjoy the episode, if you enjoy the podcast please feel free to leave a
review and or rating. In podcasting reviews and or ratings are huge and I
very much appreciate your feedback. If you would like to contact me please
email me at info.fromthespectrum.atgmail.com. Thank you for listening to
From the Spectrum podcast.