Elements of Organization
Page: 1-11 (11)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010002
PDF Price: $15
Abstract
The lives of species are trapped within ‘cooperation and conflict’. They
compete with each other to win the ‘survival of the fittest’. In cognitive
neurosciences, action and perception are the most crucial. Perception guides action by
selecting targets and correcting errors. This entire process is stored in the memory. It is
an essential part of learning and creates the basis for new knowledge by association.
Neural circuits that control metabolism and food intake are housed within the
hypothalamus. It is small in size but plays a crucial role. Temperature, sleep, eating,
and social interactions are its responsibility. Emotion and learning are related e.g.,
positive emotion (simply feeling good) motivates students to perform better. Emotion,
as the present state of knowledge stands, is taken care of by the amygdala. Should we
consider it the ‘heart of the brain’?
The purpose of this chapter is not to cover all systems or subsystems but to discuss
only a select few. This decision has been taken to reduce the complexity of the brain’s
neurovascular structure. Capillaries in the neurovascular structure hold back certain
molecules, RNA viruses, and other disease-causing agents (ions, molecules, etc). The
blood-brain barrier, cerebrospinal fluid, and blood-cerebrospinal fluid barrier are three
key elements of the organizational structure of the brain.
Neurons, Glial Cells and Imaging
Page: 12-29 (18)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010003
PDF Price: $15
Abstract
Scientists at the European Molecular Biology Laboratory have investigated
how embryonic stem cells become mature nerve cells. They assessed the complex
interplay of molecules during the differentiation process. Consequently, new insights
into the role of a protein called SOX2 in neurons emerged. This protein is expressed by
a gene, SOX2, located on chromosome 3 in humans. This gene is a sex-determining Yrelated HMG box2 and serves as a marker for neural stem and progenitor cells [1].
Progenitor stem cells become neurons and glial cells. The ratio of glia to neurons in the
human brain is 10:1. This suggests that glial cells play significant roles in cognitive
functions. Glial cells of CNS are divided into microglia and macroglia. The microglia
are macrophage-like cells, which function as a phagocyte. Macroglia consist of
astrocytes and oligodendrocytes. Oligodendrocytes act as CNS equivalent to
myelinating Schwann cells in the peripheral nervous system (PNS).
Neuroimaging is a branch of medical imaging that focuses on the brain. Among all
imaging techniques, magnetic resonance imaging (MRIs) and MEGs
(Magnetoencephalographs) are favorites of medical doctors. MRI has two variants:
functional MRI and structural MRI. In this chapter, both of them are discussed.
Detection and monitoring of the progression of neurodegenerative diseases are
performed with MEG by analyzing neural complexity and the Grassberger-Procaccia
correlation dimension. Lempel-Ziv complexity is a better option. Positron emission
tomography (PET) is a useful procedure to measure the metabolic activity of the cells
of body tissues. PET helps monitor biochemical changes in the body.
Electroencephalography is used to characterize states of consciousness of the brain.
EEG is not discussed in the present chapter since the aim of the chapter is not to
present all neuroimaging techniques but to cover a select few depending on the author’s
own background and experience.
Neural Systems in Learning and Memory
Page: 30-50 (21)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010004
PDF Price: $15
Abstract
In this chapter, theories of learning are not discussed at all. Numerous texts
exist where they can be found. It would be enough to note that behavior has two
aspects: 1) explorative and 2) exploitative in active inference. The former is sensitive
to ambiguity, and the latter is sensitive to risk. In the absence of ambiguity, active
inference reduces to a Bellman scheme [1]. Bayesian inference is integrated with active
inference in free-energy formulation. Actions are guided by predictions and are refined
by sensory feedback. The variational free energy is a function of observations and a
probability density over their hidden causative agents. The time average of energy is
action. Minimum variational free energy corresponds to a principle of least action.
Perception can be regarded as a minimum of free energy with respect to inbound
sensory information and action as a minimization of free energy with respect to
outbound action.
Synaptic modification is a prerequisite for learning to occur. What one learns must be
preserved for future use. Therefore, it needs to be stored. That storage is memory.
Neural plasticity is the basis for memory formation. Information about biologically
important events (Pavlovian conditional fear, Pavlovian conditioned eye-blink) reach
centers in the amygdala and cerebellum through circuitry, which depends on the
modality of stimulus and its complexity. In the present chapter, memory systems are
introduced to the reader, starting from the Baddeley-Hitch model of working memory.
Working memory is also known as short-term memory (STM). Certain information
stored in short-term memory is transferred to a memory system known as Long-term
memory (LTM). The brain makes decisions as to which information is to be
transferred to LTM. The role of brain oscillations in memory formation is also
discussed. 7±2 rule states that STM in humans can store only 5 pieces of information
when it is complex; on the other hand, it can store 9 pieces when information is simple.
A method to characterize the complexity of information is given. Information transport
in the brain is thoroughly discussed. The chapter ends with a discussion on the
discovery of engram cells, which participate in systems consolidation of memory.
Geometry of Navigation in Space: Neural Maps
Page: 51-60 (10)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010005
PDF Price: $15
Abstract
A cognitive map guides spatial navigation in mammals. Pyramidal neurons
in the hippocampus become active only in a particular region of the environment.
These regions are called ‘place fields’, and these neurons are called place cells. Many
brain regions are involved in the cognitive mapping of the environment. Grid cells in
the medial entorhinal cortex organize themselves on a regular grid of triangles covering
the entire surface of the environment. The firing pattern of grid cells represents the
distance between spatial locations. These distances provide spatial metrics for the
cognitive map. Other neurons that participate in spatial navigation are head direction
cells, border cells, speed cells, goal cells, reward cells, etc.
Hippocampus-entorhinal circuit provides a ‘coordinate system’ for on-line
measurement of distance and direction of landmarks defining a path leading to a goal.
Navigation of an animal toward a goal depends on synaptic plasticity. Functional
synapses are chosen from a set of anatomical synapses based on the interaction of
Hebbian learning rules, sensory feedback, attractor dynamics, and neuromodulation.
Artificial neural networks, which emulate biological neural networks, can be derived
from complete connectomes of an organism. Design and control principles underlying
intelligent autonomous control systems can be understood based on an analysis of these
ANNs.
Alzheimer’s Disease: Diagnosis and Cure
Page: 61-90 (30)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010006
PDF Price: $15
Abstract
Causative agents of Alzheimer’s disease are 1) amyloid β foldings, 2)
neurofibrillary tangles, and 3) reactive gliosis. Interaction of Aβ with the prion protein
within neurons has recently been suggested to be the basis for drug discovery. Prion
protein is a membrane protein found on cell surfaces of diverse types [1]. The
accumulation of misfolded and unfolded proteins (UP) generates stress in the
endoplasmic reticulum. This stress worsens the health of the regular function of
neuronal cells. The role of unfolded protein response in T cell development and
function has also been acknowledged [2]. The induction of Femto particles (Fps) is
proposed inside G protein-coupled receptors at an appropriate point in time to monitor
the accumulation of unfolded proteins and to control the misfolding of amyloid β.
These new particles of 10-15m are proposed to be produced in neurons of the bloodbrain barrier (BBB). Protons released by hemoglobin can be glued to their antiparticle,
i.e., antiproton, in the conformational space of partially folded amyloid β polypeptides.
Portable Penning antiproton traps are now available at CERN. Gluing of protons and
antiprotons to form a femto particle is mediated by dopamine, a neurotransmitter in
the excitatory synapses.
Intraneuronal oxygen homeostasis also contributes to the control of the progression of
the disease. Quantum entanglement between two fps (cf. Fig. 8), one in the neurons
of the neurovascular system (NVU) and the other in cerebrospinal fluid (CSF), may be
used to assess the efficiency of the process in a patient with AD. Our approach to the
discovery of a drug for AD is based on monitoring and controlling the misfolding of
amyloid β and the initiation of folding of unfolded proteins by the intervention of femto
particles.
Brain and Beauty: Neuroscience of Romanticism
Page: 91-103 (13)
Author: Vikas Rai*
DOI: 10.2174/9789815256987124010007
PDF Price: $15
Abstract
The meaning of the word “romantic”, according to Oxford Dictionary, is
having a quality that motivates emotions. It makes you think about love. One would
find the meaning of love either in the poetry of Ravindra Nath Tagore or in the poems
of Rumi. W. B. Eats defined beauty as a thing of eternal joy, which keeps on
increasing. It has no upper bound. The branch of neurosciences that connects us to the
study of literature, paintings, and movies is cognitive neuroscience. Cognition is the
process by which knowledge and understanding are developed in the mind, i.e., how
does the brain enable the mind? Now, what is mind? Mind is reflected in occurrences
such as sensations, perceptions, emotions, memories, desires, and many more. The aim
of this chapter is to elucidate the link between neuroscience and romanticism.
Language plays a central role in cognition. The effects of language on visual perception
were explored by Lupyan et al. [1]. Our ability to recognize perceptual stimuli is
dependent on the physical features of the stimuli and our prior experiences. Language
influences visual processing both offline and online. These effects are the result of a
predictive processing approach to perception. The history of English (both British and
American) literature is discussed. Poets from South Asia and the Middle East are also
covered. The chapter impresses upon the reader that poets such as Rumi, Khalid
Gibran, Mirza Ghalib and others guide us to the path of eternality. The reader will find
a few stanzas from their poems in this chapter.
Theories of action and perception are discussed in Chapter 1 under the heading
‘Reward’. Sensations, emotions, desires and empathy are the subject matter of this
chapter. This chapter will attempt to establish a link between the occurrences and the
quality, which is known as empathy. A piece of literature devoid of this quality does
not qualify to be literature. Some recent developments in neurosciences are reviewed.
Free-energy formulation of inference and learning schemas based on generative models
of the world is given. The free-energy principle provides a useful framework to
investigate neural computation and probabilistic world models.
Introduction
The Brain: A Systems Neuroscience Perspective is a comprehensive textbook designed for undergraduate students in neuroscience. It offers a detailed exploration of brain dynamics, spatial navigation, and the neuroscience of Alzheimer's disease, with an emphasis on understanding complex concepts through simplified mathematical models. The objective is to provide a solid foundation for readers in systems neuroscience. Key Topics Fundamental Brain Dynamics: Covers the basics of brain organization, neural systems, and the role of differential equations in neuroscience (Chapters 1-3). Spatial Navigation: Discusses the neural mechanisms underlying spatial navigation and the geometry of neural maps (Chapter 4). Alzheimer’s Disease: Presents a simplified mathematical theory of Alzheimer’s dementia, exploring its onset, progression, and potential interventions (Chapter 5). Key Features Accessible Approach: Minimizes mathematical complexity to make the subject approachable for readers with a basic understanding of differential equations. Standalone Resource: Provides all essential knowledge on brain function, making it a valuable tool for both coursework and self-study. Includes references for advanced readers.