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1. Is Butorphanol-induced PVN Neuronal Activation Mediated by the Kappa-Opioid Receptor? Ryan Veach
Neuroscience Scholars Summer Program
July 26, 2006
2. Butorphanol Mixed opioid agonist/antagonist
Full agonist at kappa opioid receptor
Partial agonist at mu opioid receptor
3. Clinical Uses of Butorphanol Desired Effects
Analgesia
Musculoskeletal pain, postoperative and postpartum pain, migraine
Anesthetic
Preoperative medication
Side Effects
Sedation
Decreased arterial pressure, increased cardiac workload, muscle weakness, nausea, miosis, confusion, hyperthermia, dysphoria, respiratory depression (ceiling effect), diuresis
4. Introduction to the PVN
Important in autonomic functions including feeding, thirst, cardiovascular responses, and endocrine responses to stress
Comprised of parvocellular and magnocellular neurosecretory neurons
Parvocellular neurons contain releasing factors such as CRF and are responsible for HPA axis activation
Magnocellular neurons produce vasopressin (fluid homeostasis and blood pressure regulation) and oxytocin (uterine contractility and milk ejection)
5. c-Fos Immunohistochemistry Hypothalamic slices Nissl stained for exact PVN location Six slices encompassing the entire PVN taken for staining 1Ab (1:20,000; Calbiochem) incubation for 36 hours @ 4C Vectastain ABC elite kit with DAB visualization Three consecutive slices with greatest c-Fos expression analyzed (Image J software; NIH) Image background subtracted and threshold values set to include c-Fos immunopositive cells only 400 um2 square used to encompass the bulk of the PVN and immunopositive cells counted Data expressed as c-Fos positive cell counts and c-Fos immunopositive area fraction