Neurobiology

Question 1

What are the main functions of the Frontal Lobe?

Answer 1

Involved in cognition, behavior, and motor functions

Includes the Prefrontal Cortex (PFC) with DLPFC for working memory and VMPFC for emotional regulation

Question 2

What does the DLPFC stand for and its primary function?

Answer 2

Dorsolateral Prefrontal Cortex; involved in working memory, planning, and decision-making

Question 3

What is the role of the VMPFC?

Answer 3

Emotional regulation, social decision-making, impulse control

Question 4

What are the main functions of the Parietal Lobe?

Answer 4

Somatosensation, spatial processing

Question 5

What is the primary function of the Temporal Lobe?

Answer 5

Auditory processing and memory (hippocampus lies here)

Question 6

What is the main function of the Occipital Lobe?

Answer 6

Vision

Question 7

What are the components of the Basal Ganglia?

Answer 7

Caudate, putamen, globus pallidus, substantia nigra, subthalamic nucleus

Question 8

What is the function of the Basal Ganglia?

Answer 8

Regulate voluntary movement, motor learning, and habit formation

Question 9

What is the function of the Thalamus?

Answer 9

Relay station for sensory and motor signals to the cerebral cortex; regulates consciousness, sleep, and alertness

Question 10

What role does the Hypothalamus play in the Limbic System?

Answer 10

Regulates autonomic and endocrine functions; maintains homeostasis (hunger, thirst, body temperature)

Question 11

What is the role of the Amygdala?

Answer 11

Processes emotions, especially fear and threat; involved in motivation, emotion, memory, and behavior

Question 12

What does Cytoarchitecture refer to?

Answer 12

The cellular composition of the brain’s tissues, often classified by Brodmann areas

Question 13

What is the main function of Neurons?

Answer 13

The main cellular components of the nervous system responsible for transmitting signals

Question 14

What are the types of Neurons?

Answer 14

• Multipolar neurons
• Projection neurons
• Local circuit neurons (interneurons)

Question 15

What is the function of Astrocytes?

Answer 15

• Maintain the blood-brain barrier
• Regulate neurotransmitter levels
• Provide metabolic support
• React to injury (gliosis)

Question 16

What is the role of Microglia?

Answer 16

Immune cells of the CNS; involved in phagocytosis, inflammatory response, and synaptic pruning

Question 17

What is the primary function of Oligodendrocytes?

Answer 17

Produce myelin in the CNS to increase conduction speed of action potentials

Question 18

What does Nissl Stain highlight in the brain?

Answer 18

Rough endoplasmic reticulum (Nissl substance) in neuron cell bodies

Question 19

What does Silver Stain visualize?

Answer 19

Myelinated fibers and white matter tracts

Question 20

What are Pyramidal Neurons characterized by?

Answer 20

Triangular shape, long projection axons, and glutamate neurotransmitter

Question 21

What are the key features of Non-Pyramidal Neurons?

Answer 21

Variable shape, often small, short axons, and typically use GABA neurotransmitter

Question 22

What is the significance of Computational Modeling of Neurons?

Answer 22

Studies how neuron morphology affects function, especially in pyramidal neurons

Question 23

What are the types of Corticocortical Connections?

Answer 23

• Intrinsic
• Associational
• Callosal

Question 24

What is the synthesis pathway for Norepinephrine?

Answer 24

Tyrosine → L-DOPA → Dopamine → Norepinephrine

Question 25

What are the major pathways for Norepinephrine in the brain?

Answer 25

* Cortex: attention, arousal * Limbic system: mood, stress * Spinal cord: pain modulation

Question 26

What is the association between Norepinephrine and Depression?

Answer 26

Reduced NE transmission implicated in major depressive disorder

Question 27

What is the synthesis pathway for Dopamine?

Answer 27

Tyrosine → L-DOPA → Dopamine

Question 28

What are the major dopaminergic pathways?

Answer 28

* Mesolimbic Pathway * Mesocortical Pathway * Nigrostriatal Pathway * Tuberoinfundibular Pathway

Question 29

What role does Serotonin play in the brain?

Answer 29

Influences mood, cognition, emotion, and pain modulation

Question 30

What is the synthesis pathway for Serotonin?

Answer 30

Tryptophan → 5-Hydroxytryptophan → Serotonin

Question 31

What are the clinical implications of Serotonin in Depression?

Answer 31

↓ Serotonin is associated with MDD; treated with SSRIs, SNRIs, MAOIs

Question 32

What is the synthesis pathway for Acetylcholine?

Answer 32

Choline + Acetyl-CoA → Acetylcholine

Question 33

What are the two main types of Acetylcholine receptors?

Answer 33

* Nicotinic Receptors (nAChRs) * Muscarinic Receptors (mAChRs)

Question 34

What is the role of the Basal forebrain in cholinergic pathways?

Answer 34

Involved in learning, memory, attention; degeneration in Alzheimer’s disease

Question 35

What does ACh activate at the neuromuscular junction?

Answer 35

Nicotinic receptors ## Footnote This activation leads to muscle contraction.

Question 36

What type of receptors do preganglionic fibers of the parasympathetic nervous system activate?

Answer 36

Nicotinic receptors

Question 37

What type of receptors do postganglionic fibers of the parasympathetic nervous system activate on effector organs?

Answer 37

Muscarinic receptors

Question 38

What condition is characterized by the loss of cholinergic neurons in the nucleus basalis of Meynert?

Answer 38

Alzheimer’s Disease

Question 39

What is the treatment for Alzheimer's Disease?

Answer 39

AChE inhibitors (e.g., donepezil, rivastigmine)

Question 40

What is Myasthenia Gravis associated with?

Answer 40

Autoantibodies against nicotinic receptors at the NMJ

Question 41

What is the treatment for Myasthenia Gravis?

Answer 41

AChE inhibitors (e.g., pyridostigmine)

Question 42

What does organophosphate poisoning cause?

Answer 42

Irreversible AChE inhibition → cholinergic crisis

Question 43

What is the antidote for organophosphate poisoning?

Answer 43

Atropine (muscarinic antagonist) + pralidoxime

Question 44

What does botulism do?

Answer 44

Blocks ACh release → flaccid paralysis

Question 45

From which amino acid is histamine synthesized?

Answer 45

Histidine

Question 46

What is the main enzyme involved in the synthesis of histamine?

Answer 46

Histidine decarboxylase

Question 47

Where are histaminergic neurons primarily located?

Answer 47

Tuberomammillary nucleus (TMN) of the hypothalamus

Question 48

What type of receptors are H1 and H3?

Answer 48

Histamine receptors

Question 49

What is unique about H3 receptors?

Answer 49

They are autoreceptors that modulate the release of histamine and other NTs

Question 50

How is histamine terminated in the extracellular space?

Answer 50

Degraded by histamine N-methyltransferase (HMT) and diamine oxidase (DAO)

Question 51

What is the main CNS enzyme for degrading histamine?

Answer 51

Histamine N-methyltransferase (HMT)

Question 52

Where do histaminergic neurons project to?

Answer 52

Cortex, thalamus, basal ganglia, brainstem, spinal cord

Question 53

What is the role of histaminergic projection systems?

Answer 53

Regulate global brain states like alertness and motivation

Question 54

What is a clinical consequence of first-generation H1 blockers?

Answer 54

Sedation

Question 55

What role does histamine play in insomnia?

Answer 55

Histamine promotes wakefulness

Question 56

What is the effect of GABA in the brain?

Answer 56

Inhibitory neurotransmission

Question 57

From which amino acid is GABA synthesized?

Answer 57

Glutamate

Question 58

What is the enzyme that synthesizes GABA?

Answer 58

Glutamic acid decarboxylase (GAD)

Question 59

What cofactor does GAD require?

Answer 59

Pyridoxal phosphate (vitamin B6)

Question 60

What are the two major types of GABA receptors?

Answer 60

GABA_A and GABA_B receptors

Question 61

What type of channels do GABA_A receptors activate?

Answer 61

Ligand-gated Cl⁻ channels

Question 62

What is the mechanism of action for GABA_B receptors?

Answer 62

Activate G-protein coupled inward rectifying K⁺ channels

Question 63

How is GABA removed from the synaptic cleft?

Answer 63

By GABA transporters (GAT-1, GAT-2)

Question 64

What happens to GABA in glial cells?

Answer 64

Converted back to glutamate via GABA transaminase

Question 65

What is the role of GABAergic interneurons in the cortex?

Answer 65

Control local circuits

Question 66

What condition is treated with benzodiazepines?

Answer 66

Anxiety & Panic Disorders

Question 67

What causes epilepsy in relation to GABA?

Answer 67

GABA deficiency or dysfunction

Question 68

What is the treatment for spasticity?

Answer 68

Baclofen (GABA_B agonist)

Question 69

What is the primary neurotransmitter implicated in excitotoxicity?

Answer 69

Glutamate

Question 70

What is the cycle involving glutamate and glutamine known as?

Answer 70

Glutamate–glutamine cycle

Question 71

What type of receptors are ionotropic glutamate receptors?

Answer 71

Ligand-gated ion channels

Question 72

What do NMDA receptors require for activation?

Answer 72

Glutamate + glycine/serine and membrane depolarization

Question 73

What are the two major classes of glutamate receptors?

Answer 73

Ionotropic and Metabotropic glutamate receptors

Question 74

What is the mechanism of group I metabotropic glutamate receptors?

Answer 74

Excitatory (↑ IP₃/DAG, via Gq)

Question 75

What is the primary mechanism for clearing glutamate from the synaptic cleft?

Answer 75

Excitatory amino acid transporters (EAATs)

Question 76

What condition involves excessive glutamate leading to cell death?

Answer 76

Excitotoxicity

Question 77

What is a potential consequence of glutamate dysregulation?

Answer 77

Depression

Question 78

What type of drugs are used in the treatment of treatment-resistant depression?

Answer 78

NMDA receptor antagonists (e.g., ketamine)