Brain Development Overview

Study Notes

Brain Development

Basal Telencephalon develops into the basal ganglia: striatum and amygdala
Dorsal Telencephalon develops into the neocortex
Diencephalon develops into the thalamus and hypothalamus
Midbrain includes structures like the substantia nigra, VTA, auditory and visual tecta (colliculi)
Ventricles and the cerebral aqueduct are important structures within the brain.
Neurogenesis occurs in the cortex, initially with symmetric cell division for progenitor cell expansion (radial glia), then asymmetric division to generate post-mitotic cells that migrate and differentiate
Cortical Development happens in an inside-out pattern
Final stages of brain development include: differentiation, axon guidance, synaptogenesis, target-dependent cell death, synaptic pruning
Four Lobes: frontal, parietal, temporal, and occipital lobes
Frontal Lobe contains areas like the prefrontal cortex, motor cortex, and sensorimotor cortex

Brain Structures and Function

Thalamus and Hypothalamus are key structures in the forebrain
Midbrain and Hindbrain are important for motor control and other functions
Meninges, BBB, CSF, ventricles work together to protect and nourish the brain
CSF flows in a specific direction

Imaging Techniques

MRI is a structural/static imaging technique that provides information about the general brain structure.
DTI is a structural/static technique that focuses on white matter.
PET is a functional technique that uses 2-DG to measure metabolic function, which is directly related to electrical activity.
fMRI is a functional technique that measures changes in blood flow, also related to electrical activity. It can be used to study differences between patient groups.

Chemical Senses

Taste (Gustation):
- Five tastant categories: sweet, sour, salty, bitter, umami
- Tongue, palate, and nasal cavity all contribute to taste perception
- Taste buds contain taste receptor cells
- Taste receptor cells are not neurons, but contain microvilli which receive tastant stimuli.
- Taste transduction involves local depolarizing potentials, transmitter release, and stimulation of gustatory afferents.
- Serotonin is released for salty and sour, while ATP is released for sweet, bitter, and umami.
- Salty and sour taste receptor cells are depolarized by amiloride-sensitive Na+ channels and H+ channels, respectively.
- Sweet, bitter, and umami work via GPCRs, PLC, IP3, Ca2+ release, and Ca2+-activated Na+ channels.
- Bitter receptors are the most diverse, while sweet and umami receptors are more specific.
- Central taste pathway involves cranial nerves VII, IX, and X, the NST, thalamus, and gustatory cortex.
- Taste receptor cells have a 2-week turnover rate.
Olfaction:
- Olfactory epithelium in the roof of the nasal cavity
- Olfactory receptor cells (OSNs) are true neurons, their axons form the primary sensory afferents (cranial nerve I)
- Olfactory bulb receives input from OSNs.
- Vomeronasal organ is mainly found in animals.
- Supporting cells create mucus.
- Basal cells are the progenitors of OSNs.
- Odorant transduction: odor receptors are GPCRs on cilia.
- Golf activates adenylyl cyclase to produce cAMP which opens cAMP-gated Na+ and Ca2+ channels and Cl- channels
- Olfactory receptor cells have a 4-8 week turnover rate.

Description

Explore the intricate processes of brain development, including structures such as the basal ganglia, neocortex, and the four lobes of the brain. This quiz covers neurogenesis, cortical development, and key developmental stages like synaptogenesis and synaptic pruning. Test your knowledge on how various brain regions evolve and their respective functions.