Table 4.

Responses of cultured serotonergic DR neurons to agonists under current clamp

	phenylephrine (50 μM)	bombesin (1 μM)	gastrin-releasing peptide (1 μM)
Action potentials elicited (n)	6	4	6
No response (n)	0	2	1
Hyperpolarized (n)	0	0	0

Agonists were applied for 5 sec. All neurons in this table were likely to be serotonergic, since they responded to 8-OH-DPAT with hyperpolarization. Experiments were conducted at ∼33 °C, except two neurons in the phenylephrine experiments that were recorded at room temperature. Cultures were prepared from 10 to 12- day-old rats and maintained for 10 to 19 days. 5 mM K⁺ external solution was used. n: number of neurons.