r norman <rsn_ at _comcast.net> wrote in
news:oj8kk055kltot3a30r5395vdvq9bsrmguh at 4ax.com:
>>Thank you very much, so minature potentiatals would always be of the
>>same size? So agonists at presynaptic receptors which inhibit calcium
>>channels, would effect the rate of minature potentials, but not there
>>amplitude, while the same agonist would effect the rate and amplitude
>>of spontaneous potentials?
>> Minis are often of a consistent size, but not always. Depending on
> just where you are recording, they can vary for several reasons:
> different quantities of transmitter release or different distances
> from the recording site. They do show variation, though, sometimes
> with substantial variance even though there is a single peak in the
> amplitude histogram.
>> Agents that influence vesicle release tend to alter the frequency but
> not the amplitude. Agents that influence postsynaptic response tend
> to alter the amplitude but not the frequency.
>> I don't understand the last half of your last statement. You seem to
> make a distinction between miniature potentials and spontaneous
> potentials when I just told you they were the same thing.
Oh... I thought spontaneous potentials were the result of sponateous
firing of a neuron, as against evoked firing.