Effects of supplemental choline on extracellular acetylcholine in the nucleus accumbens during normal behavior and pharmacological acetylcholine depletion

Abstract

Brain microdialysis was used to determine whether systemic or local application of choline would modify the extracellular concentration of acetylcholine (ACh) in the nucleus accumbens (NAc) of freely moving rats. Supplemental choline given intraperitoneally or into the NAc of normal rats did not increase extracellular ACh. When local ACh interneurons in the NAc were treated pharmacologically to deplete the intracellular stores of ACh, then systemic choline (80 mg/kg) was an effective treatment. Specifically, 1) blockade of the high-affinity choline transporter with hemicholinium-3 (HC-3) to reduce ACh synthesis caused a decrease in extracellular ACh, but choline supplementation restored ACh toward its normal level in the NAc. 2) Local bicuculline treatment released ACh to the point of depletion, but systemic choline or locally infused choline helped maintain normal ACh levels. These results suggest that choline supplementation might be useful in preventing depletion of ACh in the nucleus accumbens during pathological conditions.

Cholinergic modulation of nucleus accumbens medium spiny neurons

“…5) indicated that, under basal conditions, there was a substantial endogenous tone of ACh in the NAc slices. This is in line with in vivo microdialysis data on the ACh release within this ventral part of the striatum (Rada et al ., 1994). We found that this endogenous cholinergic tone may have both a nicotinic and muscarinic receptor‐mediated component.…”

“…5A1 and D1). In view of the reported endogenous steady‐state level of extracellular ACh in rat NAc in vivo (Rada et al ., 1994), we studied whether this may also occur in vitro . Indeed, both muscarinic and nicotinic receptor antagonists (i.e.…”

Long‐lasting nicotinic modulation of GABAergic synaptic transmission in the rat nucleus accumbens associated with behavioural sensitization to amphetamine

“…We cannot exclude that there is an endogenous ACh tonus present in slices from saline‐pretreated rats (Rada et al. , 1994).…”

“…We cannot exclude that there is an endogenous ACh tonus present in slices from saline-pretreated rats (Rada et al, 1994). However, possibly it is not enough or degraded at too high a rate (Zhou et al, 2002) in order to affect spontaneous or evoked GABA release.…”