HDS 110 Brain and Behavioral Development January 13

HDS 110 Brain and Behavioral Development January 13 th, 2021

Synaptogenesis • Formation of synapses between neurons • Formation of neurotransmitter release site on the presynaptic membrane • Formation of receptive field on post synaptic membrane • Two membranes are also aligned and specialized for their specific neurotransmitter • Followed by synaptic pruning (mostly postnatal) • Active synapses strengthened • Inactive ones removed

Neural Differentiation • Grow, take on a shape appropriate to location and layer • Extend axons and dendrites • Start forming synapses, connecting with other neurons • Start producing specific neurotransmitters • Create receptors to receive synaptic transmissions

Axon Pathfinding • Growth cone—Tip of growing axon that rapidly samples environment for chemical gradients. • Chemoattractive • https: //youtu. be/Wj 3 C 6 c. Lq. Xz. Y • Chemorepulsive • https: //youtu. be/t 6 c. Vtkb 9 y. HQ

Afferent Specialization • As cells begin to differentiate, they become capable of both sending and receiving information • The kind of information neurons in a particular region of cortex receive “the afferent input” helps determine the function of that region will be

Brodmann’s cytoarchitectonic map Long-standing question: When and how does this complex pattern of areal differentiation emerge in the developing cortex?

Main divisions of the brain • Cerebrum • made of two distinct hemispheres and responsible for higher brain functions including thinking and emotions • Neocortex is the cortex (“gray matter”) of 90% of cerebrum, 6 layers • Allocortex is the cortex for the olfactory system and hippocampus, 4 layers • Cerebellum • responsible for things such as balance and muscular coordination • Brain stem • responsible for basic body functions such as heartbeat regulation

Anatomy of the brain • 4 lobes of the brain • • Frontal Parietal Temporal Occipital • Adult human brain weighs about 3 pounds and is said the be the size of two fists pressed together

Functions of the brain • Frontal Lobe • cognitive functions and control of voluntary movement or activity • Parietal Lobe • processes information about temperature, taste, touch and movement • Occipital Lobe • Vision • Temporal Lobe • processes memories, integrating them with sensations of taste, sound, sight and touch • Cerebellum: Balance, coordination • Brain Stem: Blood pressure, breathing, heartbeat, swallowing

Left vs Right brain MYTH • https: //www. ted. com/talks/elizabeth_waters_the_left_brain_vs_right_brain_myth/transcript? language=en#t-205161

Phrenology MISCONCEPTION • Phrenology is the determination of a person’s mental capacity according to the shape of the skull • Stronger/larger areas = bulges in the scalp • Gall proposed the size of a brain region is directly connected to its functional strength • The idea behind phrenology stems from the notion that mental functions are localized to discrete areas of the brain (not completely wrong)

Next Class • Reading • Stiles pg. 245 -269 and 289 -299 • DWA • 5 -10 sentence summary of the processes necessary to shape the emerging cortical network (described in pg. 245 -269) • 1 quiz question and answer