Gaba b receptors activation leads to ipsp-2. gaba a receptors blockade leads to decreased cl- conductance-answer: cd (katzung, pp 345, brunton pp 330) gaba b receptors activation leads to opening of k+ channels. this causes a hyperpolarization of the postsynaptic membrane (k+ exits from the cell) and therefore the production of ipsp. gaba receptors activation directly opens cl- channels on postsynaptic membrane, so causing an increase of cl- conductance. gaba a receptors blockade does the opposite. a) gaba a ionotropic, gaba b receptors are metabotropic, i.e. g-protein coupled.. b) gaba receptors do not regulate na+ channels. e actually gaba b receptors activation leads to increased k+ conductance. gaba b receptors blockade does the opposite.