Transmitter Action, Reversal Potentials, and Post-synaptic Responses

This set of flashcards covers the mechanisms of transmitter action, ionotropic and metabotropic receptor functions, reversal potentials, and membrane integration concepts from the BI2432 lecture.

What are the two main classes of neurotransmitter receptors based on their mechanism of action?

Ionotropic receptors (directly ligand-gated) and G-protein coupled receptors (metabotropic).

What is the typical reversal potential ($E_{rev}$) for excitatory ionotropic receptors like AMPA and nicotinic acetylcholine?

Approximately $0\,mV$.

Which specific glutamate receptor is characterized by a voltage-dependent $Mg^{2+}$ block and significant $Ca^{2+}$ permeability?

NMDA receptor.

What phenomenon occurs when inhibitory conductance increases while the membrane potential ($V_m$) is near the chloride reversal potential ($E_{Cl}$), reducing EPSP size without causing hyperpolarization?

Shunting inhibition (also known as 'silent' or 'divisive' inhibition).

According to the 'Golden Rule' mentioned in the lecture, what happens to the injected current if the membrane potential ($V_m$) is above the reversal potential ($E_{rev}$)?

The injected current is hyperpolarising.

Which receptor type couples via G-proteins to opening inwardly-rectifying K+ ($KIR$) channels to produce a slow IPSP?

$GABA_B$ receptor.

Which membrane property is responsible for integrating synaptic currents and slowing the time course of depolarization compared to the current?

Membrane capacitance.

Which neuromodulator is associated with motivation and reward, acting though metabotropic receptors categorized as D1 (excitation) or D2 (inhibition)?

Dopamine.

What method of recording is used to avoid perturbing the intracellular chloride concentration ($[Cl^-]$) when studying $GABA_A$ reversal potentials?

Gramicidin perforated patch recording.

In the context of activity-dependent plasticity, what is the term for a long-term increase in EPSP amplitude following intense stimulation?

Long-Term Potentiation (LTP).