Lecture 2- Nervous system: circuits and behaviour

Question 1

what is a neural circuit

Answer 1

Population of neurons in an animal’s nervous system that carries out a specific behaviour or set of behaviours

Question 2

examples of how neural circuits can be studied

Answer 2

modified organisms, e.g. labelling neurons
histology- GFP etc used as label
imaging- addition of a fluorophore, can see when specific molecules are released

Question 3

example of a reflex in an invertebrate

Answer 3

crayfish tail flip- protection against predation
controlled by giant fibre neurons, large abdominal muscles aid investment into this

Question 4

2 types of tail flip

Answer 4

medial giant- threat from the front > moving back
lateral giant- rear threat > up and forward

Question 5

role of mechanosensors in reflexes

Answer 5

detect movement at the tail, also prevents reactivation by altering the reflex threshold following activation

Question 6

examples of object avoidance behaviours

Answer 6

signals of an object in the eye summing onto neurons in the locust brain during flight, very angular threshold leads to appropriate movement

Question 7

what is neural gating

Answer 7

filtering out of sensory stimuli at a low threshold, helps prevent ‘irrelevant’ stimuli from getting to the brain

Question 8

synaptic plasticity

Answer 8

modification of neural circuits based on learnt information

Question 9

hebbian plasticity

Answer 9

synaptic strengthening process, increased synapse number based on good outcomes

Question 10

synaptic scaling

Answer 10

weakening/downscaling of receptors to a specific thing