Effects of GABA ligands injected into the nucleus accumbens shell on fear/anxiety-like and feeding behaviours in food-deprived rats

Abstract

In an attempt to establish a relationship between food intake and fear/anxiety-related behaviours, the goal of this study was to investigate the effect of bilateral injections of GABAA (Muscimol, MUS, doses 25 and 50ng/side) and GABAB (Baclofen, BAC, doses 32 and 64ng/side) receptor agonists in the nucleus accumbens shell (AcbSh) on the level of fear/anxiety-like and feeding behaviours in 24h food-deprived rats. The antagonists of GABAA (Bicuculline, BIC, doses 75 and 150ng/side) and GABAB (Saclofen, SAC, doses 1.5 and 3μg/side) were also tested. The results indicated that the total number of risk assessment behaviour decreased after the injection of both doses of GABAA agonist (MUS) into the AcbSh of 24h food-deprived rats exposed to elevated plus maze. Similar results were obtained after treatment with both doses of GABAB (BAC) agonist in the AcbSh. These data indicated that the activation of both GABAA and GABAB receptors within the AcbSh caused anxiolysis in 24h food-deprived rats. In addition, feeding behaviour (food intake, feeding latency and feeding duration) remained unchanged after treatment with both GABA agonists. In contrast, both food intake and feeding duration decreased after injections of both doses of BIC (GABAA antagonist), while the feeding latency remained unchanged after treatment with both GABA antagonists in the AcbSh of 24h food-deprived rats. The treatment with SAC (GABAB antagonist) did not affect feeding behaviour. Collectively, these data suggest that emotional changes evoked by pharmacological manipulation of the GABA neurotransmission in the AcbSh are not linked with changes in food intake.

Ficus sycomorus extract reversed behavioral impairment and brain oxidative stress induced by unpredictable chronic mild stress in rats

“…These results suggest that the UCMS has effectively contributed in the development of anxiety in animals. This result has also been reported by Frih et al [ 26 ] and may be due to the inhibitory activity of the GABAergic system [ 43 ]. On the other hand, the treatment of anhedonic rats with F. sycomorus extracts significantly reduced the number of entries in the closed arms (100 and 200 mg/kg, p < 0.001) and the number of time spent in the closed arms (100 mg/kg, p < 0.05).…”

Disinhibition of the Nucleus Accumbens Leads to Macro-Scale Hyperactivity Consisting of Micro-Scale Behavioral Segments Encoded by Striatal Activity

“…Hyperactivity in the form of increased locomotion has been reported in studies using disinhibition of limbic territories in rats, including the NAc (Wachtel and Andén, 1978;Jones et al, 1981;Morgenstern et al, 1984) and the ventral pallidum (Mogenson and Nielsen, 1983;Austin and Kalivas, 1990), and in primates (Worbe et al, 2009). In addition, disinhibition of the NAc shell led to emotional dysregulation (Stratford and Kelley, 1997;Lopes et al, 2012), which may contribute indirectly to the observed changes in locomotion. Multiple different hyperkinetic states have been evoked using similar manipulations in the sen-sorimotor basal ganglia: disinhibition of the sensorimotor striatum leads to motor tics (Tarsy et al, 1978;McCairn et al, 2009;Bronfeld et al, 2013;Pogorelov et al, 2015;Klaus and Plenz, 2016), downstream disinhibition in the sensorimotor GPe leads to chorea (Grabli et al, 2004;Bronfeld et al, 2010) and disinhibition of the striatum in cats (Yamada et al, 1995), and the motor thalamus in primates (Guehl et al, 2000) leads to dystonia.…”

Interaction of Γ Aminobutyric Acid B Receptors and Electromagnetic Field in the Fear Response

“…The varied results of the present study from those of other studies may be related to the procedure of study. Saclofen, as GABA B antagonist, injection in nucleus accumbens shell did not affect the fear/anxiety behaviors (Lopes et al, 2012). 2-OH saclofen blocked the inhibitory effects of serotonin in the lateral amygdala: as a mechanism for modulation of sensory inputs related to fear conditioning (Stutzmann and LeDoux, 1999).…”

“…Activation of GABA B receptor in the nucleus accumbens shell decreased the level of fear/anxiety, without a positive correlation between these behaviors (Lopes et al, 2007). Lopes et al (2012) reported that the activation of both GABA A and GABA B receptors within the AcbSh can cause fear/anxiety behavior in 24 h food-deprived rats as demonstrated by this fact that the injections of both doses of the GABA A receptor agonist (muscimul) and GABA B receptor agonist (baclofen) decreased the total number of risk assessment exhibition in 24 h fooddeprived rats (Lopes et al, 2012). In the present study, CGP35348 had no effect on the frequency of fear response in rats without exposure to EMF.…”