Intravenous valproate inhibits ongoing and evoked activity of dura-sensitive thalamic neurons in rats

Blockade of 5‐HT3 receptors with granisetron does not affect trigeminothalamic nociceptive transmission in rats: Implication for migraine

“…The electrophysiological model of trigemino‐durovascular nociception, we used, is accepted as a reliable experimental tool for uncovering the neurobiology of headaches along with the mechanisms underlying therapeutic action of anti‐cephalalgic drugs and non‐pharmacological headache treatments . This model has a high degree of predictive validity and is easily integrated into pre‐clinical pharmacological screening .…”

“…Rats were anaesthetised with an intraperitoneal injection of a mixture of urethane (800 mg/kg; ICN Biomedicals, Aurora, OH, USA) and α‐chloralose (60 mg/kg; MP Biomedicals, Solon, OH, USA). All surgical procedures were performed as previously described . Briefly, once a surgical level of anaesthesia was achieved, femoral arterial and venous catheters were placed for continuous monitoring of blood pressure and drug administration, respectively.…”

“…All surgical procedures were performed as previously described. 22,24,38 Briefly, once a surgical level of anaesthesia was achieved, femoral arterial and venous catheters were placed for continuous monitoring of blood pressure and drug administration, respectively. After the trachea was exposed and a tracheal cannula was inserted, the animals were secured to a stereotaxic frame.…”

Modelling headache and migraine and its pharmacological manipulation

“…calibrated von Frey monofilaments) stimulation of the ipsilateral dura, superior sagital sinus or TG and by stimulation of the facial skin (with brush, pressure or pinch). Neuronal activity in the ventroposteromedial nucleus in response to TVS stimulation is reportedly modulated by triptans (Shields and Goadsby, 2006) as well as drugs used in migraine prophylaxis such as propranolol (Shields and Goadsby, 2005), topiramate (Andreou and Goadsby, 2011) and valproate (Sokolov et al, 2013). They also provided insight into some features of migraine headache such as its throbbing character and aggravation on coughing or bending by demonstrating that dural BJP S E Erdener and T Dalkara nociceptors become rapidly sensitized to mechanical stimuli once activated, whereas sensitization of the second-order neurons in the TCC was shown to mediate cephalic allodynia and muscle tenderness (Burstein et al, 1998;Noseda and Burstein, 2013).…”

“…Moreo-ver, electrophysiological recordings from the TCC combined with anterograde and retrograde tracing methods can be used to study modulation of the CSD-induced dural nociceptor activation by corticotrigeminal descending pathways (Noseda et al, 2010a) and to investigate the characteristics of third-order neurons in the thalamus, which has provided insights into migraine-associated symptoms such as photophobia (Noseda et al, 2010b). Neuronal activity in the ventroposteromedial nucleus in response to TVS stimulation is reportedly modulated by triptans (Shields and Goadsby, 2006) as well as drugs used in migraine prophylaxis such as propranolol (Shields and Goadsby, 2005), topiramate (Andreou and Goadsby, 2011) and valproate (Sokolov et al, 2013).…”