Table 1.

Differences in ACh and choline concentrations in response to microdialysis of mCSF and atropine in KFN, MPBN, and LPBN

	Difference in Concentration, μM/ml
	ACh		Choline
	Unilateral	Bilateral	Unilateral	Bilateral
Mean ± SE	0.18 ± 0.17	−0.63 ± 0.20	0.01 ± 0.11	−0.43 ± 0.19
t-test P value	0.929	0.027	0.936	0.053
KFN	−0.12	−1.3	−0.28	−0.04
	−0.25	−0.53	−0.16	−0.09
	+0.37	−0.08	−0.28	+0.12
	−0.15	+0.05	+0.81	−0.06
	−1.41		+0.01
			−0.09
			−0.05
			0
			−0.19
			−0.17
			−0.73
MPBN	−0.21	−1.22	−0.11	−1.18
	+0.11	−0.1	−0.06	−0.31
	+0.04	−2.26	−0.47	−0.17
	−0.03	−0.25	−0.27	−0.04
	−0.35		−0.31	−2.24
			0.00	−0.06
			0.00
			−0.62
LPBN	+1.14	−0.01	+1.36	−0.04
	+1.07	−0.59	+1.35	−1.09
	+0.02	−0.62	+0.01	−0.44

Compared with bilateral microdialysis (MD) of mock cerebral spinal fluid (mCSF), bilateral MD of atropine significantly (P < 0.05) decreased the concentrations of both ACh and choline in the effluent dialysis fluid. Unilateral MD of atropine did not significantly (P > 0.05) affect ACh or choline concentration in the effluent dialysis fluid. Each value (mean ± SE) is the difference in concentration of ACh or choline between MD of mCSF and atropine. Data were obtained during MD into the Kölliker-Fuse nucleus (KFN) and the lateral (LPBN) and medial parabrachial nuclei (MPBN). Values in bold type were obtained from studies at night, and the remainder were obtained from studies during the day. We were unable to obtain separate values at night for awake and non-rapid eye movement (NREM) sleep states.