Lecture 4

Question 1

Neurons

Answer 1

Diversity in shape, size, neurotransmitter and location. Electrically active (allow rapid and reliable communication). Synapses continue to change throughout life.

Question 2

Glia

Answer 2

‘Glue’. Different types (oligodendrocytes, astrocytes and microglia). Key roles in neural signalling, development and health ~50%brain cells.

Question 3

Cerebrum

Answer 3

cortex (perception, decisions, memory, voluntary motor), basal ganglia (motivation and movement), amygdala (fear, emotion)

Question 4

Midbrain

Answer 4

colliculi (visual and auditory reflexes), substantia Nigra

Question 4

Diencephalon

Answer 4

Hypothalamus (needs, autonomic), thalamus

Question 5

Brainstem

Answer 5

pons (motor and sensory reflexes), cerebellum (coordination of movement), medulla (breathing and heart rate)

Question 6

Spinal cord

Answer 6

Motor and sensory to body

Question 7

ventricle

Answer 7

hollow centre of tube, filled with CSF

Question 8

Folding of neural tube

Answer 8

Neural folds fold, pushing the neural plate away from the dorsal side and midline of neural plate forms neural groove. Neural folds join at the midline causing the cells of the neural groove to migrate inside and they become neural crest cells (PNS) and neural tube is CNS

Question 9

Neural circuit correspondance

Answer 9

In spinal cord, dorsal root corresponds with sensory input while ventral root corresponds with motor impit

Question 10

Formation of PNS

Answer 10

Neural crest cells migrate throughout the body and give rise to many important neural populations e.g sensory neurons (dorsal root ganglia in spinal cord and cranial), autonomic ganglia (sympathetic and parasympathetic), enteric neurons and Schwann cells

Question 11

making the ventricular zone

Answer 11

Forms early in brain development to produce progenitor cells that undergo rapid mitotic division. The first mitotic cells are radial glial cells, which serve as both neural progenitors and scaffolding for migrating neurons. As the first post-mitotic neurons are generated, they migrate superficially away from the ventricular zone. These migrating neurons begin to differentiate in a new, more superficial layer, contributing to the formation of distinct brain structures.

Question 12

Axon growth

Answer 12

axon growth cones navigate to their targets via successive turning decisions. When it arrives, it forms synapses

Question 13

refinement of connections

Answer 13

driven by experience after born. The projections are refined, removed, tighter, stronger and more precise between pre and post synapse cell

Question 14

important of repetition

Answer 14

activity patterns are important for refining synaptic connections. After birth, if some synapses are not used for any reason, their neighbours may branch and ‘take over’ more territory, increasing their synaptic effectiveness. Peak periods of refinement differ greatly between brain regions in frontal cortex, not until mid 20s

Question 15

consequences of mature brain

Answer 15

decrease processing/reaction speed, memory (executive decline), sensory perception

Question 16

changes in mature brain

Answer 16

changes to blood flow, hormones, mitochondria, DNA, accumulation of toxic and misfolded proteins, genes vs lifestyle

Question 17

influences on mature brain

Answer 17

genes, cognitive reserve (how strong circuit is/how many synapses), education, exercise, diet, sleep, alcohol, drugs, toxin exposure, stress, injury, social interaction, cognitive activities (puzzles, music, language, new places/experiences)