Fig. 8.
Biophysical properties of currents evoked by bath application of muscarine in a T stellate cell (A–D). A, Muscarine (20 μm) elicited a decrease of instantaneous current (IINS) and a negative shift of the holding current. B, The muscarine-evoked difference currents were not obviously time- and voltage-dependent. C, TheI–V relationship of the difference current was linear. The current amplitudes were averaged through the whole length of each trace. The reversal potential (−92.8 mV) was calculated from a linear fit of the measurements. D, In the presence of 1 μm atropine, muscarine did not evoke any response in the same cell whose response is shown in A.E, Application of 20 μm muscarine to a D stellate cell caused no change. Note that the hyperpolarization-activated current rises more rapidly in the D stellate cell than in the T stellate cell. The internal solution was normal. The external solution contained 0.5 μm TTX, 40 μm DNQX, and 1 μm strychnine.