scholarly journals α-Conotoxin TxIB: A Uniquely Selective Ligand for α6/α3β2β3 Nicotinic Acetylcholine Receptor Attenuates Nicotine-Induced Conditioned Place Preference in Mice

Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 490 ◽  
Author(s):  
You ◽  
Li ◽  
Xiong ◽  
Zhu ◽  
Zhangsun ◽  
...  
Keyword(s):  
Acetylcholine Receptor ◽  
Conditioned Place Preference ◽  
Nicotinic Acetylcholine Receptor ◽  
Addiction Treatment ◽  
Brain Regions ◽  
Place Preference ◽  
Enzyme Linked Immunosorbent Assay ◽  
Nicotinic Acetylcholine ◽  
Selective Ligand

Abstract: α-Conotoxin TxIB is a specific antagonist of α6/α3β2β3(α6β2*) nicotinic acetylcholine receptor (nAChR) with an IC50 of 28 nM. Previous studies have shown that α6β2* nAChRs are abundantly expressed in midbrain dopaminergic neurons and play an important role in mediating the mechanism of nicotine and other drugs reward effect. It provided important targets for the development of anti-addiction drugs. The present study evaluated the pharmacological activity of TxIB in vivo with conditioned place preference (CPP) model, which were induced by subcutaneous injection (s.c.) of nicotine (NIC, 0.5 mg/kg). α-Conotoxin TxIB inhibited the expression and reinstatement of CPP in mice dose-dependently, but had no significant effect on locomotor activity. The concentrations of dopamine (DA), γ-aminobutyric acid (GABA) and noradrenaline (NE) in different brain regions were measured by enzyme-linked immunosorbent assay (ELISA). We found that TxIB could inhibit the concentrations of DA, GABA and NE in different brain regions (such as nucleus accumbens (NAc), hippocampus (HIP) and prefrontal cortex (PFC)) in NIC-induced mice. The concentrations of DA and NE were decreased in ventral tegmental area (VTA), while GABA had little change. The current work described the inhibition activity of TxIB in NIC-induced CPP, suggesting that α6β2* nAChR-targeted compound may be a promising drug for nicotine addiction treatment.

scholarly journals Contrasting effects of the α7 nicotinic receptor antagonist methyllycaconitine in different rat models of heroin reinstatement

2021 ◽  
pp. 026988112199157
Author(s):  
Josephine Palandri ◽  
Sharon L Smith ◽  
David J Heal ◽  
Sue Wonnacott ◽  
Chris P Bailey
Keyword(s):  
Acetylcholine Receptor ◽  
Conditioned Place Preference ◽  
Nicotinic Acetylcholine Receptor ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Place Preference ◽  
Self Administration ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
Nicotinic Acetylcholine ◽  
Α7 Nicotinic Acetylcholine Receptors

Background: α7 Nicotinic acetylcholine receptors are implicated in the reinstatement of drug-seeking, an important component of relapse. We showed previously that the α7 nicotinic acetylcholine receptor antagonist, methyllycaconitine, specifically attenuated morphine-primed reinstatement of conditioned place preference in rodents and this effect was mediated in the ventral hippocampus. Aims: The purpose of this study was to evaluate α7 nicotinic acetylcholine receptor antagonism in reinstatement of the conditioned place preference for the more widely abused opioid, heroin, and to compare the effect of α7 nicotinic acetylcholine receptor blockade on reinstatement of heroin-seeking and heroin self-administration in an intravenous self-administration model of addictive behaviour. Methods: Rats were trained to acquire heroin conditioned place preference or heroin self-administration; both followed by extinction of responding. Methyllycaconitine or saline was given prior to reinstatement of drug-primed conditioned place preference, or drug-prime plus cue-induced reinstatement of intravenous self-administration, using two protocols: without delivery of heroin in response to lever pressing to model heroin-seeking, or with heroin self-administration, using fixed and progressive ratio reward schedules, to model relapse. Results: Methyllycaconitine had no effect on acquisition of heroin conditioned place preference or lever-pressing for food rewards. Methyllycaconitine blocked reinstatement of heroin-primed conditioned place preference. Methyllycaconitine did not prevent drug-prime plus cue-induced reinstatement of heroin-seeking, reinstatement of heroin self-administration, or diminish the reinforcing effect of heroin. Conclusions: The α7 nicotinic acetylcholine receptor antagonist, methyllycaconitine, prevented reinstatement of the opioid conditioned place preference, consistent with a role for α7 nicotinic acetylcholine receptors in the retrieval of associative memories of drug liking. The lack of effect of methyllycaconitine in heroin-dependent rats in two intravenous self-administration models suggests that α7 nicotinic acetylcholine receptors do not play a role in later stages of heroin abuse.

Light-Induced Calcium Influx Into Retinal Axons Is Regulated by Presynaptic Nicotinic Acetylcholine Receptor Activity In Vivo

1999 ◽  
Vol 81 (2) ◽  
pp. 895-907 ◽  
Author(s):  
James A. Edwards ◽  
Hollis T. Cline
Keyword(s):  
Acetylcholine Receptor ◽  
Nicotinic Acetylcholine Receptor ◽  
Visual Stimulus ◽  
Optic Tectum ◽  
Visual Stimulation ◽  
Calcium Influx ◽  
Nicotinic Acetylcholine ◽  
Retinal Axons ◽  
Retinotectal System

Light-induced calcium influx into retinal axons is regulated by presynaptic nicotinic acetylcholine receptor activity in vivo. Visual activity is thought to be a critical factor in controlling the development of central retinal projections. Neuronal activity increases cytosolic calcium, which was hypothesized to regulate process outgrowth in neurons. We performed an in vivo imaging study in the retinotectal system of albino Xenopus laevis tadpoles with the fluorescent calcium indicator calcium green 1 dextran (CaGD) to test the role of calcium in regulating axon arbor development. We find that visual stimulus to the retina increased CaGD fluorescence intensity in retinal ganglion cell (RGC) axon arbors within the optic tectum and that branch additions to retinotectal axon arbors correlated with a local rise in calcium in the parent branch. We find three types of responses to visual stimulus, which roughly correlate with theon, off, and sustained response types of RGC reported by physiological criteria. Imaging in bandscan mode indicated that patterns of calcium transients were nonuniform throughout the axons. We tested whether the increase in calcium in the retinotectal axons required synaptic activity in the retina; intraocular application of tetrodotoxin (10 μM) or nifedipine (1 and 10 μM) blocked the stimulus-induced increase in RGC axonal fluorescence. A second series of pharmacological investigations was designed to determine the mechanism of the calcium elevation in the axon terminals within the optic tectum. Injection of bis-( o-aminophenoxy)- N, N, N′, N′-tetraacetic acid-AM (BAPTA-AM) (20 mM) into the tectal ventricle reduced axonal calcium levels, supporting the idea that visual stimulation increases axonal calcium. Injection of BAPTA (20 mM) into the tectal ventricle to chelate extracellular calcium also attenuated the calcium response to visual stimulation, indicating that calcium enters the axon from the extracellular medium. Caffeine (10 mM) caused a large increase in axonal calcium, indicating that intracellular stores contribute to the calcium signal. Presynaptic nicotinic acetylcholine receptors (nAChRs) may play a role in axon arbor development and the formation of the topographic retinotectal projection. Injection of nicotine (10 μM) into the tectal ventricle significantly elevated RGC axonal calcium levels, whereas application of the nAChR antagonist αBTX (100 nM) reduced the stimulus-evoked rise in RGC calcium fluorescence. These data suggest that light stimulus to the retina increases calcium in the axon terminal arbors through a mechanism that includes influx through nAChRs and amplification by calcium-induced calcium release from intracellular calcium stores. Such a mechanism may contribute to developmental plasticity of the retinotectal system by influencing both axon arbor elaboration and the strength of synaptic transmission.

scholarly journals α-Conotoxin TxID and [S9K]TxID, α3β4 nAChR Antagonists, Attenuate Expression and Reinstatement of Nicotine-Induced Conditioned Place Preference in Mice

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 646
Author(s):  
Xiaodan Li ◽  
Shen You ◽  
Jian Xiong ◽  
Yamin Qiao ◽  
Jinpeng Yu ◽  
...  
Keyword(s):  
Smoking Cessation ◽  
Locomotor Activity ◽  
Conditioned Place Preference ◽  
Addiction Treatment ◽  
Nicotine Addiction ◽  
Place Preference ◽  
Inhibition Activity ◽  
Nicotinic Acetylcholine ◽  
The World ◽  
Superior Effect

Tobacco smoking has become a prominent health problem faced around the world. The α3β4 nicotinic acetylcholine receptor (nAChR) is strongly associated with nicotine reward and withdrawal symptom. α-Conotoxin TxID, cloned from Conus textile, is a strong α3β4 nAChR antagonist, which has weak inhibition activity of α6/α3β4 nAChR. Meanwhile, its analogue [S9K]TxID only inhibits α3β4 nAChR (IC50 = 6.9 nM), and has no inhibitory activity to other nAChRs. The present experiment investigates the effect of α3β4 nAChR antagonists (TxID and [S9K]TxID) on the expression and reinstatement of nicotine-induced conditioned place preference (CPP) and explores the behaviors of acute nicotine in mice. The animal experimental results showed that TxID and [S9K] TxID could inhibit the expression and reinstatement of CPP, respectively. Moreover, both had no effect in acute nicotine experiment and the locomotor activity in mice. Therefore, these findings reveal that the α3β4 nAChR may be a potential target for anti-nicotine addiction treatment. [S9K]TxID, α3β4 nAChR antagonist, exhibit a superior effect for anti-nicotine addiction, which is promising to develop a novel smoking cessation drug.

Sign in / Sign up

Export Citation Format

Share Document