Biological Psychology: Brain Development and Nervous System Organization

Flashcards covering brain development stages, neuronal processes, neuroanatomy terms, neurotransmitters, pharmacology, and neuronal signaling.

What is the process of gastrulation?

The process where a hollow ball of undifferentiated, pluripotent cells (blastula) becomes a multi-layered structure (gastrula) that eventually forms different body tissues.

How is neurulation defined in embryonic development?

The process in which the neural plate folds to form the neural tube, which develops into the central nervous system (brain and spinal cord).

What are the three main divisions of the embryonic brain visible at approximately $4$ weeks?

Prosencephalon (forebrain), Mesencephalon (midbrain), and Rhombencephalon (hindbrain).

Into which two structures does the Prosencephalon (forebrain) further divide?

Telencephalon and Diencephalon.

Into which two structures does the Rhombencephalon (hindbrain) further divide?

Metencephalon and Myelencephalon.

What are the five main processes of neuronal development in the brain?

1. Proliferation (cell production), 2. Differentiation (cell specialization), 3. Migration (neuronal cell movement), 4. Synaptogenesis (synapse formation), 5. Myelination (white matter production).

What is the specific role of the DCDC2 gene according to Meng et al. (2005)?

A polymorphism of the DCDC2 gene is reported to cause up to $20\%$ of dyslexia cases by disrupting neuronal migration and the formation of brain circuits for reading.

What protein is required for successful synapse formation and function during development?

Neural Growth Factor (NGF), which is a type of neurotrophin secreted by a neuron's target cells.

Define apoptosis in the context of the nervous system.

A genetically programmed mechanism of cell death that occurs in neurons that fail to make appropriate synaptic connections or receive sufficient neurotrophins like NGF.

What is the primary function of the nervous system?

To speed, integrate, and coordinate physiological and behavioral responses to changes in the internal (homeostasis) and external (sensory/motor) environments.

In neuroanatomy, what do the terms 'Afferent' and 'Efferent' signify?

Afferent (sensory) carries information from the periphery to the CNS; Efferent (motor) carries information from the CNS to the periphery.

What are the four main types of sensory receptor neurons?

Photoreceptors (light), Mechanoreceptors (mechanical force), Thermoreceptors (temperature changes), and Chemoreceptors (chemical changes).

How is the Autonomic Nervous System (ANS) divided?

It is divided into the Sympathetic division (Fight or Flight) and the Parasympathetic division (Rest or Digest).

What are the anatomical components of a nerve?

A nerve consists of a bundle of fasciculi covered in epineurium. Each fasciculus is a bundle of nerve fibres covered by endoneurium and bound by perineurium.

What is the difference between Grey Matter and White Matter?

Grey Matter consists mainly of neuronal cell bodies (somata), while White Matter consists of a high concentration of myelinated axons (tracts).

What findings did Maguire et al. (2000) report regarding London taxi drivers?

There is a correlation between hippocampal volume change and the amount of time spent working as a taxi driver.

According to Gaser & Schlaug (2003), how does the brain of a professional musician differ from a non-musician?

They have thicker grey matter in areas for hand control and vision, and their right temporal lobe is $30\%$ larger.

How many pairs of spinal nerves are in the human body?

$31$ pairs.

What is decussation?

The crossing over of sensory and motor tracts, which occurs mostly in the brainstem.

Which neurotransmitter is primarily depleted in Alzheimer's Disease?

Acetylcholine (ACh).

Which neurotransmitter is implicated in Parkinson's Disease due to low levels?

Dopamine (DA).

What are the common medical uses for Cannabis mentioned in the lecture?

Bronchodilation for asthma, anti-emetic (reducing nausea from chemotherapy), reducing intra-ocular pressure in glaucoma, and lowering blood pressure.

What is the role of Astrocytes in the Central Nervous System?

They provide 3D structural support, envelope synapses, act as a reserve fuel source, and regulate blood flow via end feet on blood vessels.

What is the function of Microglia?

They are phagocytic scavenger cells that clear extracellular debris and serve as the main immune response in the CNS.

What value represents the resting potential of a neuron?

$-70\,mV$.

What is the function of the sodium-potassium pump in a resting neuron?

It maintains ionic concentrations by pumping $3\,Na^+$ out of the cell for every $2\,K^+$ pumped into the cell.

At what threshold does an action potential typically trigger?

$-55\,mV$.

What is the peak voltage reached during an action potential?

$+40\,mV$.

Compare the propagation speed of myelinated A$\alpha$ fibres to non-myelinated C-fibres.

Myelinated A$\alpha$ fibres conduct at $80\,m\,s^{-1}$ to $120\,m\,s^{-1}$, while non-myelinated C-fibres conduct at $0.5\,m\,s^{-1}$ to $2.0\,m\,s^{-1}$.

What is the main pharmacological mechanism for treating Parkinson's Disease?

Administration of L-Dopa (a DA precursor) along with a dopa decarboxylase inhibitor, as only $5-10\%$ of L-Dopa crosses the blood-brain barrier (BBB).

What is the core premise of the 'chemical imbalance' theory of mental illness?

The idea that mental illness is caused by a chemical imbalance that drugs work to correct, though this is debated as an over-simplification (Aspirin analogy).

Where is the primary reward system pathway located in the brain?

A dopamine pathway that goes from the ventral tegmental area (VTA) to the nucleus accumbens (NAc).

What is the difference between a receptor agonist and receptor antagonist?

An agonist binds to and mimics the neurotransmitter, while an antagonist binds to and blocks the receptor.

What characterizes the 'Parasympathetic' division of the autonomic nervous system?

It controls 'Rest or Digest' functions such as constricting pupils, stimulating salivation, slowing heartbeat, and stimulating digestion.

What characterizes the 'Sympathetic' division of the autonomic nervous system?

It controls 'Fight or Flight' responses such as dilating pupils, accelerating heartbeat, inhibiting digestion, and stimulating adrenaline release.