When brains expand: mind and the evolution of cortex

2007 ◽  
Vol 19 (3) ◽  
pp. 139-148 ◽  
Author(s):  
Matthew T. K. Kirkcaldie ◽  
Peter D. Kitchener
Keyword(s):  
Empirical Support ◽  
Brain Regions ◽  
Human Mind ◽  
The Body ◽  
Primate Species ◽  
Alternative View ◽  
Brain Morphometry ◽  
Self Recognition ◽  
Fresh Perspective ◽  
Functionally Diverse

Objective:To critically examine the relationship between evolutionary and developmental influences on human neocortex and the properties of the conscious mind it creates.Methods:Using PubMed searches and the bibliographies of several monographs, we selected 50 key works, which offer empirical support for a novel understanding of the organization of the neocortex.Results:The cognitive gulf between humans and our closest primate relatives has usually been taken as evidence that our brains evolved crucial new mechanisms somehow conferring advanced capacities, particularly in association areas of the neocortex. In this overview of neocortical development and comparative brain morphometry, we propose an alternative view: that an increase in neocortical size, alone, could account for novel and powerful cognitive capabilities. Other than humans’ very large brain in relation to the body weight, the morphometric relations between neocortex and all other brain regions show remarkably consistent exponential ratios across the range of primate species, including humans. For an increase in neocortical size to produce new abilities, the developmental mechanisms of neocortex would need to be able to generate an interarchy of functionally diverse cortical domains in the absence of explicit specification, and in this respect, the mammalian neocortex is unique: its relationship to the rest of the nervous system is unusually plastic, allowing great changes in cortical organization to occur in relatively short periods of evolution. The fact that even advanced abilities like self-recognition have arisen in species from different mammalian orders suggests that expansion of the neocortex quite naturally generates new levels of cognitive sophistication. Our cognitive and behavioural sophistication may, therefore, be attributable to these intrinsic mechanisms’ ability to generate complex interarchies when the neocortex reaches a sufficient size.Conclusion:Our analysis offers a parsimonious explanation for key properties of the human mind based on evolutionary influences and developmental processes. This view is perhaps surprising in its simplicity, but offers a fresh perspective on the evolutionary basis of mental complexity.

Neuromodulatory Feedback to the Inferior Colliculus

2018 ◽  
pp. 576-610 ◽  
Author(s):  
Laura Hurley
Keyword(s):  
Inferior Colliculus ◽  
Auditory System ◽  
Auditory Processing ◽  
Internal State ◽  
Brain Regions ◽  
Auditory Information ◽  
Situational Variables ◽  
Acoustic Stimuli ◽  
Functionally Diverse ◽  
Behavioral Information

The inferior colliculus (IC) receives prominent projections from centralized neuromodulatory systems. These systems include extra-auditory clusters of cholinergic, dopaminergic, noradrenergic, and serotonergic neurons. Although these modulatory sites are not explicitly part of the auditory system, they receive projections from primary auditory regions and are responsive to acoustic stimuli. This bidirectional influence suggests the existence of auditory-modulatory feedback loops. A characteristic of neuromodulatory centers is that they integrate inputs from anatomically widespread and functionally diverse sets of brain regions. This connectivity gives neuromodulatory systems the potential to import information into the auditory system on situational variables that accompany acoustic stimuli, such as context, internal state, or experience. Once released, neuromodulators functionally reconfigure auditory circuitry through a variety of receptors expressed by auditory neurons. In addition to shaping ascending auditory information, neuromodulation within the IC influences behaviors that arise subcortically, such as prepulse inhibition of the startle response. Neuromodulatory systems therefore provide a route for integrative behavioral information to access auditory processing from its earliest levels.

scholarly journals Cannabinoid receptors distribution in mouse cortical plasma membrane compartments

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hajar Miranzadeh Mahabadi ◽  
Haseeb Bhatti ◽  
Robert B. Laprairie ◽  
Changiz Taghibiglou
Keyword(s):  
Plasma Membrane ◽  
Lipid Raft ◽  
Cannabinoid Receptors ◽  
Gradient Centrifugation ◽  
Brain Regions ◽  
Cb1 Receptor ◽  
The Body ◽  
Cb2 Receptor ◽  
Cortical Tissue ◽  
Ionic Detergent

AbstractThe type 1 and type 2 cannabinoid receptors (CB1 and CB2 receptors) are class A G protein-coupled receptors (GPCRs) that are activated by endogenous lipids called endocannabinoids to modulate neuronal excitability and synaptic transmission in neurons throughout the central nervous system (CNS), and inflammatory processes throughout the body. CB1 receptor is one of the most abundant GPCRs in the CNS and is involved in many physiological and pathophysiological processes, including mood, appetite, and nociception. CB2 receptor is primarily found on immunomodulatory cells of both the CNS and the peripheral immune system. In this study, we isolated lipid raft and non-lipid raft fractions of plasma membrane (PM) from mouse cortical tissue by using cold non-ionic detergent and sucrose gradient centrifugation to study the localization of CB1 receptor and CB2 receptor. Lipid raft and non-lipid raft fractions were confirmed by flotillin-1, caveolin-1 and transferrin receptor as their protein biomarkers. Both CB1 receptor and CB2 receptor were found in non-raft compartments that is inconsistent with previous findings in cultured cell lines. This study demonstrates compartmentalization of both CB1 receptor and CB2 receptor in cortical tissue and warrants further investigation of CB1 receptor and CB2 receptor compartmental distribution in various brain regions and cell types.

scholarly journals Region-specific elevations of glutamate + glutamine correlate with the sensory symptoms of autism spectrum disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jason L. He ◽  
Georg Oeltzschner ◽  
Mark Mikkelsen ◽  
Alyssa Deronda ◽  
Ashley D. Harris ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Strong Support ◽  
Empirical Support ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Resonance Spectroscopy ◽  
Primary Sensorimotor Cortex ◽  
Spectrum Disorders ◽  
Inhibitory Signaling

AbstractIndividuals on the autism spectrum are often reported as being hyper- and/or hyporeactive to sensory input. These sensory symptoms were one of the key observations that led to the development of the altered excitation-inhibition (E-I) model of autism, which posits that an increase ratio of excitatory to inhibitory signaling may explain certain phenotypical expressions of autism spectrum disorders (ASD). While there has been strong support for the altered E-I model of autism, much of the evidence has come from animal models. With regard to in-vivo human studies, evidence for altered E-I balance in ASD come from studies adopting magnetic resonance spectroscopy (MRS). Spectral-edited MRS can be used to provide measures of the levels of GABA + (GABA + macromolecules) and Glx (glutamate + glutamine) in specific brain regions as proxy markers of inhibition and excitation respectively. In the current study, we found region-specific elevations of Glx in the primary sensorimotor cortex (SM1) in ASD. There were no group differences of GABA+ in either the SM1 or thalamus. Higher levels of Glx were associated with more parent reported difficulties of sensory hyper- and hyporeactivity, as well as reduced feed-forward inhibition during tactile perception in children with ASD. Critically, the finding of elevated Glx provides strong empirical support for increased excitation in ASD. Our results also provide a clear link between Glx and the sensory symptoms of ASD at both behavioral and perceptual levels.

Refining the Effects Observed in a Developmental Neurobehavioral Study of Ammonium Perchlorate Administered Orally in Drinking Water to Rats. II. Behavioral and Neurodevelopment Effects

2005 ◽  
Vol 24 (6) ◽  
pp. 451-467 ◽  
Author(s):  
Raymond G. York ◽  
John Barnett ◽  
Michael F. Girard ◽  
David R. Mattie ◽  
Marni V. K. Bekkedal ◽  
...  
Keyword(s):  
Drinking Water ◽  
Ammonium Perchlorate ◽  
Brain Regions ◽  
Male Rats ◽  
Male Rat ◽  
Sprague Dawley ◽  
Continuous Access ◽  
Brain Morphometry ◽  
The Central Nervous System ◽  
The Right

A developmental neurotoxicity study was conducted to generate additional data on the potential functional and morphological hazard to the central nervous system caused by ammonium perchlorate in offspring from in utero and lactation exposure. Female Sprague-Dawley rats (23 to 25/group) were given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 10.0 mg/kg-day perchlorate in the drinking water beginning 2 weeks prior to mating and continuing through day 10 of lactation for the behavioral function assessment or given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 30.0 mg/kg-day beginning on gestation day 0 and continuing through day 10 of lactation for neurodevelopment assessments. Motor activity was conducted on postpartum days 14, 18, and 22 and juvenile brain weights, neurohistopathological examinations, and regional brain morphometry were conducted on postpartum days 10 and 22. This research revealed a sexually dimorphic response, with some brain regions being larger in perchlorate-treated male rats than in comparable controls. Even so, there was no evidence of any obvious exposure-related effects on male rat brain weights or neuropathology. The most consistent exposure-related effect in the male pups was on the thickness of the corpus callosum, with both the right- and left-sided measures of the thickness of this white matter tract being significantly greater for the male pups in the 0.1 and 1.0 mg/kg-day exposure groups. The behavioral testing suggests prenatal exposure to ammonium perchlorate does not affect the development of gross motor movements in the pups.

scholarly journals Relationships between dietary macronutrients and adult neurogenesis in the regulation of energy metabolism – CORRIGENDUM

2013 ◽  
Vol 111 (4) ◽  
pp. 755-755
Author(s):  
Marianne A. Yon ◽  
Suzanna L. Mauger ◽  
Lucy C. Pickavance
Keyword(s):  
Body Weight ◽  
Energy Metabolism ◽  
Adult Neurogenesis ◽  
Brain Regions ◽  
The Body ◽  
Adult Brain ◽  
Metabolic Dysfunction ◽  
Neurogenic Niche ◽  
Normal Limits ◽  
Simple Carbohydrates

Of the environmental factors which have an impact on body weight, nutrients are most influential. Within normal limits, hypothalamic and related neuronal populations correct perturbations in energy metabolism, to return the body to its nutritional set-point, either through direct response to nutrients or indirectly via peripheral appetite signals. Excessive intake of certain macronutrients, such as simple carbohydrates and SFA, can lead to obesity and attendant metabolic dysfunction, also reflected in alterations in structural plasticity, and, intriguingly, neurogenesis, in some of these brain regions. Neurogenesis, previously thought to occur only in the embryo, is now known to take place in the adult brain, dependent on numerous stimulating and inhibiting factors, including dietary components. Because of classic associations between neurogenesis and the hippocampus, in learning and cognition, this brain region has also been the focus of attention in the study of links between diet and neurogenesis. Recently, however, a more complete picture of this relationship has been building: not only has the hypothalamus been shown to satisfy the criteria for a neurogenic niche, but appetite-related mediators, including circulating hormones, such as leptin and ghrelin, pro-inflammatory cytokines and the endocannabinoid intracellular messengers, are also being examined for their potential role in mediating neurogenic responses to macronutrients. The present review draws together these observations and investigates whether n-3 PUFA may exert their attenuating effects on body weight through the stimulation of adult neurogenesis. Exploration of the effects of nutraceuticals on neurogenic brain regions may encourage the development of new rational therapies in the fight against obesity.

scholarly journals Population-specific brain [18F]-FDG PET templates of Chinese subjects for statistical parametric mapping

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hongkai Wang ◽  
Yang Tian ◽  
Yang Liu ◽  
Zhaofeng Chen ◽  
Haoyu Zhai ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Statistical Parametric Mapping ◽  
Brain Regions ◽  
Brain Images ◽  
Parametric Mapping ◽  
Brain Morphometry ◽  
Brain Pet ◽  
Positron Emission ◽  
The Family ◽  
Function Impairment

AbstractStatistical Parametric Mapping (SPM) is a computational approach for analysing functional brain images like Positron Emission Tomography (PET). When performing SPM analysis for different patient populations, brain PET template images representing population-specific brain morphometry and metabolism features are helpful. However, most currently available brain PET templates were constructed using the Caucasian data. To enrich the family of publicly available brain PET templates, we created Chinese-specific template images based on 116 [18F]-fluorodeoxyglucose ([18F]-FDG) PET images of normal participants. These images were warped into a common averaged space, in which the mean and standard deviation templates were both computed. We also developed the SPM analysis programmes to facilitate easy use of the templates. Our templates were validated through the SPM analysis of Alzheimer’s and Parkinson’s patient images. The resultant SPM t-maps accurately depicted the disease-related brain regions with abnormal [18F]-FDG uptake, proving the templates’ effectiveness in brain function impairment analysis.

scholarly journals Truth, body and religion

2011 ◽  
Vol 23 ◽  
Author(s):  
Jarl-Thure Eriksson
Keyword(s):  
Human Mind ◽  
The Body ◽  
Religious Context ◽  
New Information ◽  
Concept Of Truth ◽  
Stored Information

This paper is based on the words of welcome to the symposium on Religion and the Body on 16 June 2010.  In a religious context ‘truth’ is like a mantra, a certain imperative to believe in sacred things. The concept of truth and falseness arises, when we as humans compare reality, as we experience it through our senses, with the representation we have in our memory, a comparison of new information with stored information. If we look for the truth, we have to search in the human mind. There we will also find religion.

scholarly journals Ecstasy from a physiological point of view

1982 ◽  
Vol 11 ◽  
pp. 74-86 ◽  
Author(s):  
Kaj Björkqvist
Keyword(s):  
Religious Tradition ◽  
Mental States ◽  
Human Mind ◽  
Point Of View ◽  
The Body ◽  
Biological Study ◽  
Physiological Basis ◽  
Slowing Down ◽  
Psychosomatic Diseases ◽  
The Brain

The biological study of man is one of today's most rapidly advancing sciences. There is no reason for not utilizing these methodologies of research and the knowledge already gained when studying ecstasy and other similar religious phenomena. Drugs have been used in all parts of the world as an ecstasy technique. Since mental states and physiological correlates always accompany each other, it is obvious that the human mind can be affected by external means, for instance by drugs. But the opposite is also true; mental changes affect the body, as they do in the case of psychosomatic diseases. Ecstasy is often described as an extremely joyful experience; this pleasure must necessarily also have a physiological basis. It is of course too early to say anything for certain, but the discovery of pleasure centres in the brain might offer an explanation. It is not far-fetched to suggest that when a person experiences euphoric ecstasy, it might, in some way or other, be connected with a cerebral pleasure center. Can it be, for example, that religious ecstasy is attained only by some mechanism triggering off changes in the balance of the transmitter substances? Or is it reached only via a change in the hormonal balance, or only by a slowing down of the brain waves, or is a pleasure centre activated? When a person is using an ecstasy technique, he usually does so within a religious tradition. When he reaches an experience, a traditional interpretation of it already exists.

scholarly journals Public justification and expert disagreement over non-pharmaceutical interventions for the COVID-19 pandemic

2021 ◽  
pp. medethics-2021-107671
Author(s):  
Marcus Dahlquist ◽  
Henrik D Kugelberg
Keyword(s):  
Empirical Support ◽  
The State ◽  
Alternative View ◽  
Public Justification ◽  
Standard View ◽  
School Closures ◽  
Environmental Cleaning ◽  
Wide Range ◽  
Cleaning And Disinfection ◽  
Pharmaceutical Interventions

A wide range of non-pharmaceutical interventions (NPIs) have been introduced to stop or slow down the COVID-19 pandemic. Examples include school closures, environmental cleaning and disinfection, mask mandates, restrictions on freedom of assembly and lockdowns. These NPIs depend on coercion for their effectiveness, either directly or indirectly. A widely held view is that coercive policies need to be publicly justified—justified to each citizen—to be legitimate. Standardly, this is thought to entail that there is a scientific consensus on the factual propositions that are used to support the policies. In this paper, we argue that such a consensus has been lacking on the factual propositions justifying most NPIs. Consequently, they would on the standard view be illegitimate. This is regrettable since there are good reasons for granting the state the legitimate authority to enact NPIs under conditions of uncertainty. The upshot of our argument is that it is impossible to have both the standard interpretation of the permissibility of empirical claims in public justification and an effective pandemic response. We provide an alternative view that allows the state sufficient room for action while precluding the possibility of it acting without empirical support.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

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