brain-cortex

self-studied neuroscience/brain research

[brain-cortex]

The Blue Spot

The locus coeruleus, or 'blue spot,' is a tiny cluster of cells at the base of the brain.

In the brain, alpha oscillations around a 10 Hertz frequency suppress active processing of sensory inputs as neural rhythms. The blue spot's noradrenaline can suppress alpha generators in the thalamus, regulating the brain’s sensitivity to relevant information.

Source

[brain-cortex]

Neuron Respiration

Nerve cells go through cellular respiration.

It is how they generate enough energy for neural cellular activity.

Glucose metabolism:

Glucose enters the cell through glucose transporters and is phosphorylated by hexokinase to produce glucose-6-phosphate (glucose-6P).

Glucose-6P is processed through one of three main metabolic pathways.

(i) glycolysis- produces two molecules of pyruvate and ATP and NADH.

Pyruvates enter mitochondria, where they are metabolized through the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, producing ATP and CO2 while consuming oxygen. Under conditions with not enough oxygen or depending on cellular metabolic profile, a pyruvate can also be reduced to lactate by lactate dehydrogenase. This lactate can be released in the extracellular space through monocarboxylate transporters. Complete oxidation of glucose produces large amounts of energy in the form of ATP in the mitochondria (30–36 ATPs) when compared to glycolysis (2 ATP).

(ii) pentose phosphate pathway (PPP)

Forms reducing equivalents in the form of NADPH. The NADPH produced in the PPP provides defense against oxidative stress through metabolism of the tripeptide glutathione (GSH). GSH is an electron donor in several reactions including ROS. The oxidized glutathione (GSSG) formed as a result is recycled back to glutathione by glutathione reductase using NADPH as an electron donor.

(iii) glucose-6P can be used in astrocytes to store glucosyl units of glycogen.

ScienceDirect

[brain-cortex]

Frontal lobe meningioma (growth)

Dementia patients may experience extreme anxiety about upcoming events in this feature within Godot syndrome.

American Journal of Medical Sciences

Dementia Neuropsychology - Science Open

[brain-cortex]

Types of Neurons

unipolar- single extension of an axon extends from the cell body and ends in dendrites (*pseudounipolar cells can branch into two sections).

bipolar- one axon and one dendrite extend from both sides of the soma. A retinal bipolar cell is an example, where the cell receives signals from photoreceptor cells sensitive to light and transmits these signals to ganglion cells that carry the signal to the brain.

multipolar (most common) - contains one axon and multiple dendrites. The Purkinje cell, a multipolar neuron in the cerebellum, has many branching dendrites, but only one axon. Multipolar neurons can be found in the central nervous system (brain and spinal cord).

pyramidal - a pyramid shaped soma surrounded by two sets of dendritic trees. The basal dendrites stem from the base of the cell body and apical dendrites stem from the apex of the body.

[brain-cortex]

Apraxia

a motor-speech disorder occurring from brain damage to the motor and frontal corteces of the cerebrum.

inhibits accurate movement and speech.

melo-kinetic apraxia.

actions, tool use, and associations.

verbal apraxia.

Wernicke's area and Broca’s area are weakly connected. This causes an error in understanding and producing language.

[brain-cortex]

OXT - Release in the Brain

Oxytocin pathways; OXT release to receptors in limbic regions and the peripheral nervous system.

The hormone oxytocin is the “love" or "hugging hormone,” created during social contact and helping to build relationships through empathy. A mother produces oxytocin when giving birth to her newborn child.

This hormone is notable for feelings of intimacy, during which organisms interact with one another out of compassion. It is one of the “feel-good" hormones influencing both mood and an increase of happiness/pleasure. What may oxytocin do in regards to social disorders?

Image: Grinevich, V. ; Neumann, I.D. (2020, Jun 8). Brain oxytocin: How puzzle stones from animal studies translate into psychiatry.

[brain-cortex]

Cognitive Boosting for Schizophrenia

Schizophrenia, characterized by psychotic symptoms such as hallucinations and delusions, also brings declined ability in learning and perceiving. This is scarcely treated in this disorder, however clinicians and neuropsychiatrists have not yet been approved for a drug in cognitive symptoms.

Barbara Sahakian has been working on cognitive training with patients at the University of Cambridge Behavioral and Clinical Neuropsychiatric Institute to help improve their episodic memory. The process includes playing games to encourage working memory. It is her first step in helping patients with their cognitive ability and aptitude.

Serious Science. (2016, Nov 7). Cognitive-enhancing drugs - Barbara Sahakian / Serious science [Video]. YouTube.

[brain-cortex]

Dissociative Identity Disorder

A small percentage of people in the world (1%) have DID, where alternate identities exist in the mind and come into present consciousness at random times. These alternate personalities have their own character traits and contain separate temperaments.

Image: Nguyen, D.Q. (2015, March 16). Dissociative identity disorder & actors/actresses. WordPress.

One of the world’s first individuals to be diagnosed with DID was Clara Norton Fowler, who owned three distinct personalities and could not recognize them. She visited a Boston neurologist who told her he could “heal” the condition with a reconciliation of personalities, but later wrote he had never seen anything like it before.

[brain-cortex]

Cerebrospinal Fluid vs. Alzheimer’s

While asleep, our cerebrospinal fluid flows through the outside of the brain’s blood vessels, removing brain cell waste and preventing the buildup of amyloid-beta protein. This protein is linked to Alzheimer’s and accumulates in cells to become amyloid plaque after many stages. When in excess, this protein can disrupt communication between neurons, and eventually causes cell destruction.

Sources: Alzheimer’s Association. (2017, March). Beta-amyloid and the amyloid hypothesis. Alzheimer’s Association. Wood, Charlie. (2019, May 21). The fibers that slow down the brain. BrainFacts.

[brain-cortex]

Have you heard?: Cerebrovascular Disease

Atherosclerosis, a buildup and fats and cholesterol inside and on the arteries, can cause restriction of blood flow to the heart and brain. This brings on cerebrovascular disease, which restricts oxygen flow and causes potential brain damage.

Mayo Clinic (2021). Atherosclerosis. Mayo Foundation for Medical Education and Research.