Probing Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices via Laser Flash Photolysis of Photoactivatable Nicotine.

Acetylcholine (ACh) acts through receptors to modulate a variety of neuronal processes, but it has been challenging to link ACh receptor function with subcellular location within cells where this function is carried out. To study the subcellular location of nicotinic ACh receptors (nAChRs) in native brain tissue, an optical method was developed for precise release of nicotine at discrete locations near neuronal membranes during electrophysiological recordings. Patch-clamped neurons in brain slices are filled with dye to visualize their morphology during 2-photon laser scanning microscopy, and nicotine uncaging is executed with a light flash by focusing a 405 nm laser beam near one or more cellular membranes. Cellular current deflections are measured, and a high-resolution three-dimensional (3D) image of the recorded neuron is made to allow reconciliation of nAChR responses with cellular morphology. This method allows for detailed analysis of nAChR functional distribution in complex tissue preparations, promising to enhance the understanding of cholinergic neurotransmission.

Non-suicidal self-injury by intravenous application of nicotine in a patient with borderline personality disorder resulting in substance dependence.

BACKGROUND: Non-suicidal self-injury in many different forms is a classic struggle for those diagnosed with borderline personality disorder (BPD). Some common ways of NSSI are cutting, scratching and head-banging. CASE DESCRIPTION: A 23-year old woman with BPD presented in our clinic with a 4-month history of intravenous application of a liquid dosage form of nicotine that is generally used for nasal application. Accordingly, the patient developed nicotine dependency (ICD-10 F17.25). Before her admission to our ward the daily intravenous nicotine application was around 33 mg. The in-patient detoxification proceeded without a remarkable withdrawal syndrome. CONCLUSION: A case of regular intravenous administration of nicotine has been observed, apparently resulting in nicotine dependence in a person with borderline personality disorder. The original intent appears to have been self-harm.