Neuroanatomy
The spinal cord is _ to the cerebellum
Caudal
Afferent vs. Efferent (define+examples)
Afferent: nerves transmit sensory signals from PNS to CNS (neuron carrying auditory info from ear to brain)
Efferent: transmit command signals from CNS to PNS (neuron in spinal cord controlling digestive muscles of gut)
Name two lobes of the brain and their functions.
Bonus: Point to them on your head.
What is the frontal lobe? What is motor control, speech, decision making, personality, & other higher cognitive functions?
What is the parietal lobe? What is somatosensory processing?
What is the occipital lobe? What is visual processing?
What is the temporal lobe? What is memory formation and auditory processing?
The neocortex is special because it is only found in __
Mammalian Brains
CNS/PNS
CNS: brain, spinal cord
PNS: all other nerves
Can you break down the PNS further?
A signal travelling from your hand to your spinal cord when you touch something hot is __?
Afferent
Diverging vs. Converging Integration
Diverging: a sensory signal transmitted to multiple brain regions
Converging: many inputs required to activate motor neuron
BONUS: describe feedback inhibition
The hippocampus and amygdala share these two functions.
What is the formation of memories and emotional responses?
Compared to cats or rats, humans have more cortex dedicated to __ __
Association Areas
Can activate one brain area to see if it is sufficient to generate behavior
Can lesion one brain area to see if that area is necessary for the behavior
If you feel a poke on your right foot, the sensation is processed on __ side of your brain.
Contralateral
Sensory, Motor, Interneuron (give examples)
Sensory: neuron responding to visual/auditory/light info
Motor: neuron at neuromuscular junction
Interneuron: Neuron in spinal cord transmitting between sensory and motor to relay info and enable reflexes
The thalamus, hypothalamus, brainstem, and basal ganglia all have this feature in common.
What are nuclei (defined clusters of neuron cell bodies)?
The thalamus contains dozens of nuclei and is the critical relay for the flow of sensory information from PNS to neocortex.
The hypothalamus and brainstem contain dozens of nuclei. Each nucleus is involved in regulating some basic functions, including sleep, body temperature, hunger, thirst, digestion, heart rate, breathing, sexual arousal, and attachment behaviors.
The basal ganglia contains a set of nuclei involved in voluntary motor movements & learning.
Both humans and drosophila share __ ___ throughout their nervous systems
bilateral symmetry
Glia example
ependymal cells- cerebrospinal fluid
oligodedrocytes (CNS) Schwann cells (PNS)- myelin
astrocytes- blood-brain barrier
microglia- immune system cells
Ganglia
Knee Jerk Reflex (4 steps)
1. sensory neuron detects mech stimulation
2. sensory neuron stimulates a motor neuron that stimulates quads
3. sensory neuron also stimulates an interneuron that INHIBITS a motor neuron stimulating hamstrings
4. quadriceps contract, hamstring relaxes -> KICK!
Bonus: What would happen if the interneuron was excitatory?
This would happen if a person was missing their cerebellum.
What is unsteady walk, slightly slurred speech, shaky handwriting, etc.?
Green algae uses channelsrodopsin for _____
phototaxis.
Compare and Contrast with Drosophila Nervous System
Drosophila~10,000 neurons, no neocortex, sugar-sensing neurons
Humans~86 billion neurons, more complex
Both have similar lobe like design and both have CNS/PNS
The __ __ separates the frontal lobe from the parietal lobe.
central sulcus
Synaptic Integration (give example of rule for hypothetical circuit given that excitatory neurons a and b synapse on c)
c only fires when a AND b do
Name the structure immediately above the brainstem.
What is the thalamus?
Bonus: Name the structure to the left of the brainstem and slightly below the thalamus.
Name a downside of using c. elegans as a model organism
What is there are so few neurons that there are a lot of different functions for the same neuron? Therefore, it is hard to observe connections.
Derived from single-cell alga
can be used for optogenetics (can transgenically express these light-activated ion channels in neurons of other animals) ex. transgenic xenopus frog egg that is depolarized when you shine light on it
Basically can use it to manipulate neural activity!