Harmane inhibits serotonergic dorsal raphe neurons in the rat

Abstract

Nicotine, harmane, and befloxatone inhibit the activity of raphe serotonergic neurons. Therefore, at least two tobacco compounds, nicotine and harmane, inhibit the activity of serotonergic neurons. The mechanism by which harmane inhibits serotonergic dorsal raphe neurons is likely unrelated to a MAO-A inhibitory effect.

The effect of CA1 dopaminergic system in harmaline-induced amnesia

“…The b-carboline alkaloids indicate modest affinity to 5-HT, dopamine and benzodiazepine receptors (Glennon et al, 2000). These alkaloids influence central neurotransmitters such as dopamine (Moura et al, 2006;Nasehi et al, 2010Nasehi et al, , 2012, via inhibition of monoamine reuptake systems (Kleven and Woolverton, 1993;Baum et al, 1996;Yang et al, 2011), and inhibition MAO-A or B (Glennon et al, 2000;Touiki et al, 2005). Some evidences displayed that harmaline change the extracellular and tissue level of dopamine (Kim et al, 1970;Glick et al, 1994Glick et al, , 1996.…”

“…The D1 receptor interacts with the Gs complex to activate adenyl cyclase, but the D2 interacts with Gi to inhibit cyclic adenosine monophosphate production (Bressan and Crippa, 2005;Ferreira et al, 2011). Some evidence reported that harmaline could influence dopaminergic transmission (Kim et al, 1970;Palmery et al, 1992), which may be done by inhibition of MAO-A or MAO-B (Herraiz and Chaparro, 2005;Touiki et al, 2005;Talhout et al, 2007;Yang et al, 2011). Since harmaline and dopamine receptors have interaction (Kim et al, 1970;Palmery et al, 1992), and considering the role of dopamine receptors (Kandel and Weeks, 1995;Wise, 2004;de Lima et al, 2011), harmaline (Meignin et al, 1999), and hippocampus (Whishaw, 1998;Burgess et al, 2002;Harvey, 2003;Faerber et al, 2007) in memory process, we attempt to determine the role of harmaline and dopamine receptors in memory acquisition and locomotor activity in the step-down passive avoidance and open field test.…”

Impact of Tobacco Regulation on Animal Research: New Perspectives and Opportunities

“…These compounds are MAO inhibitors (Herraiz, 2004) and may contribute to the MAO inhibition observed in smokers at the concentrations present in cigarette smoke (Rommelspacher, Meier-Henco, Smolka, & Kloft, 2002). However, they also appear to have actions independent of MAO inhibition (Arib et al, 2010;Rommelspacher et al, 2002;Touiki, Rat, Molimard, Chait, & de Beaurepaire, 2005). Large doses of norharman enhance responding for nicotine in rats on a progressive ratio, but not an FR, schedule of reinforcement (Guillem et al, 2006).…”

Effects of tobacco and cigarette smoke extracts on serotonergic raphe neurons in the rat

“…For instance b-carbolines (harmane and norharmane) and monoamine oxidase inhibitors (MAOI, harmane and norharmane) activate dopaminergic and noradrenergic neurons, and that harmane, but not norharmane, inhibits serotonergic neurons (see Ref. [3] for review). Given acutely, MAOI-A, but not MAOI-B, inhibits serotonergic neurons [3].…”

“…[3] for review). Given acutely, MAOI-A, but not MAOI-B, inhibits serotonergic neurons [3]. Monoamine oxidase inhibition may also be necessary to set up nicotine dependence [4].…”