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Updated: Sep 26, 2026
In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration
Published on: June 15, 2018
Methyllycaconitine fails to inhibit electrically precipitated tonic hindlimb extension in mice
Stephen I Deutsch1, Richard B Rosse, Alan S Bellack
1Mental Health Service Line, Veterans Integrated Service Network, Linthicum, Maryland, USA. Stephen.Deutsch@med.va.gov
Abstract:
Abnormalities of the transduction of the acetylcholine signal in the brain by the alpha(7) nicotinic receptor are thought to contribute substantially to a fundamental pathophysiologic mechanism in schizophrenia. Abnormal or diminished expression of the alpha(7) nicotinic receptor polypeptide subunit in the brains of patients with schizophrenia has encouraged consideration of the development of alpha(7) nicotinic receptor agonist strategies for the treatment of this disorder. These strategies would target negative symptoms, and attentional and cognitive abnormalities, which are domains of psychopathology that are associated with very poor functional outcomes and disability. Unfortunately, a major theoretic limitation to the development of alpha(7) nicotinic receptor agonist interventions for the pharmacotherapy of schizophrenia is the development of seizures. In the current study, intraperitoneally administered methyllycaconitine, a selective alpha(7) nicotinic receptor antagonist, was shown to be unable to antagonize electrically precipitated seizures in mice. These data suggest that the alpha(7) nicotinic receptor does not mediate this type of seizure activity in mice. Also, although the medication-induced emergence of seizure activity remains a real concern with the development of alpha(7) nicotinic receptor agonist strategies, the data suggest that there should be lessened concern about precipitating seizures related to electrically precipitated tonic hindlimb extension in mice.
Insights
Alpha-7 nicotinic receptor antagonists do not appear to cause seizures in mice, suggesting a reduced risk for this side effect in potential schizophrenia treatments targeting these receptors. This finding may alleviate concerns regarding seizure activity in future drug development.
Area of Science:
- Neuroscience
- Pharmacology
- Psychiatry
Background:
- Alpha-7 nicotinic receptors are implicated in schizophrenia pathophysiology.
- Reduced expression of alpha-7 nicotinic receptors is observed in schizophrenia patients.
- Alpha-7 nicotinic receptor agonists are being explored for treating schizophrenia's negative and cognitive symptoms.
Purpose of the Study:
- To investigate the role of alpha-7 nicotinic receptors in seizure activity.
- To assess the potential for seizure induction by alpha-7 nicotinic receptor antagonists.
- To evaluate the safety of developing alpha-7 nicotinic receptor agonist therapies for schizophrenia.
Main Methods:
- Administration of methyllycaconitine, a selective alpha-7 nicotinic receptor antagonist, to mice.
- Induction of seizures via electrical stimulation.
- Observation of antagonist effects on seizure precipitation and severity.
Main Results:
- Methyllycaconitine did not antagonize electrically precipitated seizures in mice.
- These findings suggest alpha-7 nicotinic receptors do not mediate this specific type of seizure.
- The study indicates a potentially lower risk of seizures related to electrically induced tonic hindlimb extension.
Conclusions:
- Alpha-7 nicotinic receptors may not be the primary mediators of electrically induced seizures in mice.
- This research could lessen concerns about seizure side effects associated with alpha-7 nicotinic receptor agonist development for schizophrenia.
- Further research is warranted to fully understand the relationship between alpha-7 nicotinic receptor modulation and seizure activity.
