Table 1

Regional distribution of [³H]AVM B_1a binding sites in rat brain

Region	Specific Binding^1-a
Region	dpm/mg protein	Relative to whole brain
Whole brain	23,652 ± 1,986	100 ± 8
Cerebellum	31,968 ± 1,838	135 ± 8
Cerebral cortex	26,049 ± 2,239	110 ± 9
Striatum	24,242 ± 1,525	102 ± 6
Pons and medulla	19,004 ± 1,185	80 ± 5
Midbrain	17,887 ± 1,185	76 ± 5
Hypothalamus	12,467 ± 1,611	53 ± 7

Synaptic membranes (0.1 mg protein) were incubated with 1.0 nM [³H]AVM B_1a at 24°C for 30 min. Nonspecific binding was determined in the presence of 3 μM unlabeled AVM B_1a. Data represent the means of three experiments with S.E. values.

↵1-a Specific binding as percent of total binding was 66 ± 6% with cerebellum, 58 to 61 ± 5% with cerebral cortex, striatum and whole brain, 48 to 51 ± 6% with pons and medulla and with midbrain and 35 ± 4% with hypothalamus.