Figure 1.
Simultaneous recording of membrane potential and [Ca2+]i in SCN neurons. A, Example of the recording setup showing a coronal hypothalamic slice and the placement of stimulating and recording microelectrodes. A bipolar electrode positioned in the optic chiasm was used to stimulate the RHT. B, An SCN neuron recorded with a microelectrode filled with an internal solution containing the [Ca2+]i-sensitive probe fura-2, which diffuses into the soma and dendritic arbor. C, Estimated (Est.) [Ca2+]i changes evoked in the soma and dendrites of a voltage-clamped SCN neuron (inset) by 10 stimuli (10 Hz; arrow) applied to the optic chiasm. D, Dendritic [Ca2+]i response was both larger in amplitude and faster to decay than in the soma, showing a clockwise hysteresis-loop temporal relationship.