title: A novel method for subarachnoid drug delivery in the medullary region of rats.
abstract: This study describes a novel method for direct subarachnoid drug delivery to the medullary dorsal horn region of rats, without introducing a catheter. The reliability of the method was demonstrated by a pharmacological validation; that is, morphine administration to the medullary region blocked the nociceptive response to formalin injected in the temporomandibular joint (TMJ) region, an effect that was prevented by co-administration of naloxone. The method proposed offers many advantages over the existing methods for medullary drug delivery with catheter implantation. It is easy to be employed, it does not induce any sign of motor impairment, and it does not require the neck surgery performed to implant a catheter in the medullary dorsal horn region. Therefore, it is a useful method for subarachnoid drug delivery in behavioral trigeminal pain studies, particularly when nociceptive behavioral measures that require normal neck muscle activity to occur, such as head withdraw or head flinch, are evaluated.
authors: Laboratory of Orofacial Pain, Department of Physiology, Faculty of Dentistry of Piracicaba, University of Campinas-Unicamp, Av. Limeira 901, CEP 13414-900, Piracicaba, São Paulo, Brazil.
authors: Luana
authors: L
authors: Fischer
authors: Carlos Amílcar
authors: CA
authors: Parada
authors: Cláudia Herrera
authors: CH
authors: Tambeli
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage; D000818:Animals; D018771:Arthralgia / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods*; D019416:Head Movements / Q000187:drug effects / Q000502:physiology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology / Q000601:surgery*; D008845:Microinjections / Q000295:instrumentation / Q000379:methods*; D009020:Morphine / Q000008:administration & dosage*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009334:Neck Muscles / Q000187:drug effects / Q000502:physiology; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods; D009619:Nociceptors / Q000502:physiology; D010147:Pain Measurement; D051381:Rats; D017208:Rats, Wistar; D013346:Subarachnoid Space / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery*; D013594:Syringes / Q000592:standards; D013705:Temporomandibular Joint Disorders / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D014275:Trigeminal Caudal Nucleus / Q000187:drug effects / Q000502:physiology / Q000601:surgery
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone; D009020:Morphine