Spindle Neurons-Von Economo Neurons

[Biomiast]

Hi to all,

After reading a little about spindle neurons, I think they have so much to offer and they deserve a seperate thread where we can post the results of our researchs, since the session thread is somewhat crowded, osit.

Here is what I have found thus far:

The best researcher studying spindle neurons is probably John Allman in Caltech. I was reading his papers, referenced by go2 in this post. To somewhat echo that post, there is a paper of Allman describing how gut feelings are related to VENs. It is called Intuition and autism: a possible role for Von Economo neurons

Serotonin 2b receptor

The serotonin 2b receptor is strongly expressed on the VENs (Figure 4c) and is rarely expressed elsewhere in the central nervous system [20]. However, the serotonin 2b receptor is also strongly expressed in the human stomach and intestines where it promotes contractions of the smooth muscles responsible for peristalsis [21]. Serotonin might serve as an antagonistic signal to dopamine, with serotonin signaling punishment and dopamine signaling reward [22]. The activation of the serotonin 2b receptor on VENs might be related to the capacity of the activity in the stomach and intestines to signal impending danger or
punishment (literally ‘gut feelings’) and thus might be an opponent to the dopamine D3 signal of reward expectation. The outcome of these opponent processes could be an evaluation by VEN of the relative likelihood of punishment versus reward and contribute to ‘gut level’ or intuitive decision-making in a given behavioral context.

I am not sure about this but I always thought serotonin is make someone calmer, as in the case we take 5-HTP, I am not sure how it is related to punishment and dopamine is related to reward, any thoughts on that? My understanding was that dopamine is reward in the sense that "getting higher" and serotonin eliminates feelings of guilt, fear etc. And research about violent behaviour showed that the reason for violent behaviour is not lack of serotonin, it is the abundance of serotonin as in the case of MAO-A gene which can't breakdown serotonin and lead to violent behaviour. It could be there is a specific mechanism for VENs that are different from other neurons and they respond to serotonin differently, or am I wrong on that one?

Here is a bit more about gut feelings:

The presence of a serotonin receptor on the VEN that is otherwise rare in the brain, but common in the viscera, suggests an interesting extension of the concept that these areas are monitoring activity in the gut. Perhaps, the expression of the serotonin 2b receptor on the VEN represents a transposition of this function from the gut into the brain, which would enable the organism to react more quickly to threatening circumstances than if it depended solely on monitoring sensations arising from the gut.

Here the paper discusses the role of Frontoinsular cortex and Anterior Cingular Cortex and their role in intuition:

Frequently we do not have the luxury of sufficient time to perform deliberative cost-benefit analyses to determine the most appropriate course of action, but instead must rely on rapid intuitive judgments. ACC and FI are active when subjects make decisions under a high degree of uncertainty [17]. These areas are involved in the subjective experience of pain[25], which is powerfully magnified by uncertainty. These areas are also active when subjects experience guilt, embarrassment and engage in deception [26–28]

The role of VENs on social emotions that is lack in psychopaths though they don’t put it like that:

Because social emotions by their very nature involve considerable uncertainty, and because social interactions are often of a rapidly changing nature, an impairment of the VEN system would be predicted to compromise social function ing. The lack of quick social intuitions is a key deficit in autism spectrum disorders.

There is another article which mentions the connection between Spindle Neurons and Agenesis of Corpus Callosum which means the disruption of the development of the region that connects two brain hemispheres. It is called “Selective reduction of Von Economo neuron number in agenesis of the corpus callosum”.Here is the description in the paper:

(AgCC) can all have signifcant effects on social and emotional behaviors, including a reduction in affective range[10, 32], an inability to express one’s emotional state (a condition called alexithymia [19, 56]), and diffculty intuiting the emotional states of others [5, 62]. AgCC in particular is associated with deficits in self- and social-awareness that can impair such capacities as humor [6], non-literal or affective language [34], and social judgment [5], suggesting that the abnormal development of the corpus callosum and surrounding midline brain structures may be particularly detrimental to socially relevant aspects of emotional cognition.

Sounds like psychopathy isn’t it? I mean obviously, one isn’t a psychopath just because they have AgCC(and they are more rare than psychopaths) but I thought if Corpus Callosum agenesis is related to VEN number and it is related to psychopathy, that would be interesting as one of the possible reasons.

I think I should also put that bit as a reminder:

In human fMRI experiments, ACC and FI are both activated by paradigms evoking social emotions such as empathy [47], guilt [46], unfairness [48], humor [60], embarrassing situations or violations of social norms [4], and romantic love [3, 23]

To lead to another interesting disorder called frontotemporal dementia:

In frontotemporal dementia(FTD), a disorder that profoundly disrupts social functioning and self-awareness, there is a 74% reduction in the VEN population relative to controls, and many of the remaining VENs are severely dysmorphic [44, 45]. Patients with FTD experience focal degeneration of both ACC and FI, accompanied by severe defcits in self-awareness, empathy, “theory of mind,” and moral reasoning

And appearently they have difficulties with language, planning and regulating their behaviour:

Behavioural symptoms include lethargy and aspontaneity or oppositely disinhibition. Apathetic patients may become socially withdrawn and stay in bed all day or no longer take care of themselves. Disinhibited patients can make inappropriate (sometimes sexual) comments or perform inappropriate acts. Patients with FTD can sometimes get into trouble with the police because of inappropriate behaviour such as stealing. Recent findings indicate that psychotic symptoms are rare in FTD, possibly due to limited temporal-limbic involvement in this disorder.

It is interesting because different people respond differently to this dementia, some develop lethargy, yet others experience disinhibition. I know little about VENs but from I know they can generate quite different responses in different people, as in the case of this dementia.

Executive function is the cognitive skill of planning and organizing. Patients become unable to perform skills that require complex planning or sequencing.

Language skills can be affected in a number of ways with two broad patterns. Some patients remain fluent with normal phonology and syntax but increasing difficulty with naming and word comprehension, known as semantic dementia in which there is atrophy of the anterior temporal lobes, typically with an asymmetric pattern. Other patients, by contrast, present with a breakdown in speech fluency due to articulation difficulty, phonological and/or syntactic errors but preservation of word comprehension, referred to as progressive nonfluent aphasia.

http://en.wikipedia.org/wiki/Frontotemporal_dementia

Here you see again the lack of VENs result in two diferent language responses. I think semantic aphasia was the term used for psychopathy, wasn’t it? I thought it may be similar to semantic dementia, descriptions somewhat resemble, or so I think.

As the result of their research regarding VEN number and AgCC they found that there is a significant reduction in VENs in a AgCC patient, yet since it is only one person they aren’t sure of their conclusions. They also show that partial corpus callosum supports VENs to some extent, but there is still an unequal ratio of VENs vs. Other neurons in both cases, AgCC being the most extreme one.

The targets of VEN projections remain unknown, and although we have reason to believe that VENs are long-distance projection neurons, it is not known if they project inter-hemispherically through the corpus callosum. Therefore, our analyses cannot distinguish whether the reduction in VEN fraction seen in AgCC is a direct result of the interruption of callosal connections, or if the reduction is a secondary consequence of developmental malformations associated with the disorder. In either case, our results offer important evidence of a localized neuronal origin for the social and emotional deficits that are associated with AgCC. This result is consistent with that observed in frontotemporal dementia [44]. It remains to be seen if VEN populations are reduced in other neuropathologies in which social/emotional deficits are a component.

In conclusion they are not sure if VENs are less because of AgCC or there is another cause that is effecting both VEN numbers and AgCC.

Even though the conclusion is somewhat ambigious, the best part of the paper was:

In immunocytochemical studies done in normal brains in our laboratory (Nicole Tetreault and John Allman), the VENs selectively express the product of the gene Disc1 (disrupted in schizophrenia). Disc1 regulates neuronal migration and the dendritic morphology of postnatally generated neurons in mice [11].

So what is significant about this? Disc-1 is a gene as the name implies disrupted in schizophrenia. So one might speculate the lack of this gene is the reason that schizophrenics might be open to realities we are not. And just the fact that it is selectively expressed in VENs opens up all kinds of possibilities. Is this gene prevent us from attaining higher consciousness by messing with the VENs? And remember that C’s said their function is Consciousness Orientation. It also brought this to my mind:

Q: Was the thought that I had one night that, at some point in time something may happen that will turn genes on in our bodies that will cause us to physically transform, an accurate perception of what could happen?
A: For the most part, yes.
Q: Are there any limitations to what our physical bodies can transform to if instructed by the DNA? Could we literally grow taller, rejuvenate, change our physical appearance, capabilities, or whatever, if instructed by the DNA?
A: Receivership capability.
Q: What is receivership capability?
A: Change to broader receivership capability...
Q: (A) It means how good is your receiver.
A: Yes.
Q: (L) What is your receiver? The physical body?
A: Mind through central nervous system connection to higher levels.
Q: So, that is the whole issue of gaining knowledge and developing control over your body. If your mind and CNS are tuned to higher levels of consciousness, that has significance in terms of your receivership capability?
A: Close.

I don’t see a better candidate than VENs to do this job with my current understanding, and if they are not controlled by genes like Disc-1, who knows what is possible in the future… Of course it is important to develop the ability to control other parts of your brain through the Work, otherwise there is no use for activation of VENs, since you would be a schizophrenic as well. This reminded me what Laura said about Shamans:

It could even be said that persons who "go mad," are "failed shamans" who have failed either because of a flaw in the transmission of the genetics, or because of environmental factors. At the same time, there are many more myths of failed Shamanic heroes than of successful ones, so the warnings of what can happen have long been in place. Mircea Eliade remarks that:

... The mentally ill patient proves to be an unsuccessful mystic or, better, the caricature of a mystic. His experience is without religious content, even if it appears to resemble a religious experience, just as an act of autoeroticism arrives at the same physiological result as a sexual act properly speaking (seminal emission), yet at the same time is but a caricature of the latter because it is without the concrete presence of the partner. [Eliade, Shamanism, 1964]

http://www.cassiopaea.org/cass/wave12e1.htm

I decided to check if somebody studied Corpus Callosum’s connection to psychopathy and I found one! It is called: "Corpus Callosum Abnormalities
in Psychopathic Antisocial Individuals".

Imagine my happiness at that time, but appearently, the result of second group indicates the increased size of corpus callosum leads to psychopathy, not a decreased size. The way they do the study is, they observed the higher the size of Corpus Callosum as the individuals get the higher the score on Psychopathy Checklist, the research was done with 83 men.

Well, it is pretty confusing, but I was thinking maybe what matters for VENs is that it should be at right size, both bigger and smaller size of corpus callosum leads to disruption of VENs in some sense, but this is purely speculation on my part.

Interestingly, the research indicates low spatial IQ in both AgCC patients and psychopaths, so throughout the paper, authors always use the word abnormality instead of increase in size. Yet at a point they mention their reasoning:

Low spatial IQ was observed in the psychopathic antisocial group and was additionally associated with increased estimated callosal volume. These associations are of interest for 3 reasons. First, agenesis of the corpus callosum and split-brain surgery have been associated with poor spatial ability. Second, low spatial but not verbal ability early in life has been found to characterize lifelong antisocial individuals. Third, the same correlation between increased estimated callosal volume and low spatial IQ has also been found in neurofibromatosis. These findings, in turn, suggest that callosal abnormalities may account for the spatial deficits in psychopathic antisocial individuals and that increased callosal volume relative tonormal is disadvantageous rather than beneficial.

Some of this stuff is really confusing for me, so if anyone detects a mistake, and points it out, I would be grateful. Any thoughts on the subject are welcomed.

I still have some papers to read, hopefully I will read them and report back soon.