Question

IMAGE K shows single-channel recordings from an ionotropic receptor, that were made using the cell-attached patch-clamp configuration. All ion concentrations are as with normal neurons, and ENa = +60 mV, EK = -80 mV, and ECl = -70 mV. In these traces, the membrane potential is being held at -60 mV. In the top trace, the experimenter stimulated the presynaptic neuron with no drug present, and in the bottom trace they had applied a drug. Unfortunately, the experimenter forgot which drug they had applied (there is a reason we say to always write everything down in your lab notebook). Based on the information you have about the experiment, including the data in IMAGE K, which of the following is the most likely candidate drug the experimenter used when recording the bottom trace?

	a.	Atropine (a mAChR antagonist)
	b.	Diazepam (a benzodiazepine)
	c.	Memantine (an NMDAR antagonist)
	d.	Nicotine (a nAChR agonist)
	e.	Pentobarbital (a barbiturate)

Answer 1

B)Diazepam: It is because diazepam causes increase in frequency of opening of Channel present in inotropic receptor(GABA receptor to be precise)

e)phenobarbital causes increase in duration of opening of ion channels.

c)memantine is a blocker so it decreases frequency of ion channel stimulation.

a)Atropine does not act on ion channel as its receptor is a g coupled receptor.(muscarinic receptor)

d)Nicotine just activates the receptor but does not cause overstimulation of it.