ELM 9.2 Flashcards
Which intracellular signalling molecule is involved in the actions of serotonin in Aplysia gill reflex sensitization?
a. cAMP b. Calcium c. DAG d. IP3
a
serotonin increase production of cAMP which then activates protein kinase A - pKA may well act to phosphorylate potassium channels and inactivate them - this depolarizes the presynaptic membrane, leading to increased neurotransmitter release
Which of the following statements about the Aplysia nervous system is correct?
a. Aplysia has a relatively large central brain b. All of its ganglia are paired c. The abdominal ganglion controls its heart rate d. The cerebral ganglion is located just above the animal's spinal cord
c
the abdominal ganglion controls heart rate - this ganglion is not paired - aplysia does not really have a central brain - its equivalent of a brain is the anterior nerve ring - its neurons are actually very big - it is an invertebrate so by definition does not have a spinal cord
Ivan Pavlov conducted a classic series of condition experiments in dogs. At the end of Pavlov’s experiment:
a. The bell is the conditioned stimulus b. The bell is the unconditioned stimulus c. Food is the conditioned stimulus d. The dog is the unconditioned stimulus
a
Sensitisation of the gill withdrawal reflex of Aplysia involves:
a. a decrease in active synaptic zones at the sensory-motor neuron interface b. activation of the cAMP cascade in the presynaptic (sensory) cell c. release of glutamate by the facilitating interneuron d. the sensory neuron running out of neurotransmitter
b
this process involves activation of the cAMP cascade in the presynaptic (sensory) cell
What is the mechanism for synaptic depression that underlies habituation of the gill withdrawal reflex in Aplysia?
a. Desensitization of postsynaptic neurons b. Inadequate repolarisation of the presynaptic neuron c. Reduced calcium influx in the presynaptic neuron d. The sensory neuron running out of neurotransmitter
c
this is due to a reduction in the Ca2+ influx per action potential leading to reduced transmitter release
how many neurons do aplysias have?
20000
there are two types of learning in aplysia. what are they?
non-associative learning
associative learning
three things under non-associative learning
- habituation : loss of response because of repeated stimulus
- dishabituation : recovery of innate response
- sensitization : response stronger than normal
what is under associative learning
classical conditioning
define non-associative learning
change as a function of experience - doesn’t matter when the stimulus is in order to elicit a response
unconditioned stimulus in regards to pavlov’s experiment
giving food without bell
unconditioned response in pavlov’s experiment
bell - no response
conditioned stimulus in pavlov
bell + food - salivation
conditioned response
bell no food - salivation
backwards pairing
unconditioned stimulus comes before the conditioned stimulus
forward pairing
conditioned stimulus comes before unconditoned stimulus
aplysia’s NS consists of _______________ and these communicate through ____________. as well, they are arranged in _____________________
ganglia
connectives
bilaterally symmetrical pairs
the abdominal ganglion in an aplysia are ________, and their function is to control ____________ (3). they contain __________________________, ___________________, and __________________ involved in the ___________ withdrawal reflex
unpaired
heart rate, blood circulation, and respiration
primary sensory neurons, interneurons and motor neurons involved in the gill and siphon
serotonin, when present, temporarily _______
closes potassium channels (s current) in sensory neuron
when serotonin is present, repolarization of membrane potential is ___________
then there is an increase in _______ influx
and therefore an increase in ________ release and enhanced ______
slowed
calcium
transmitter
excitability
cAMP acts as a ________ and activates _____
second messenger
PKA
active PKA _______ substrate proteins
phosphorylates
