JOURNAL ARTICLE

Noradrenaline inhibits substantia gelatinosa neurons in mice trigeminal subnucleus caudalis via alpha(2) and beta adrenoceptors

Seong Kyu Han, Jung Ran Park, Seon Ah Park, Sang Woo Chun, Jeong Chae Lee, So Yeong Lee, Pan Dong Ryu, Soo Joung Park
Neuroscience Letters 2007 January 10, 411 (2): 92-7
17110030
The actions of noradrenaline (NA) in the substantia gelatinosa (SG) are important for their antinociceptive effects. In order to identify the possible mechanisms underlying NA actions in the SG of trigeminal subnucleus caudalis (Vc), the direct membrane effects were examined by gramicidin-perforated patch clamp recording using brain slice preparation from immature mice brainstem. The majority (60/71, 85%) of neurons tested were hyperpolarized by NA application, and these hyperpolarizing effects were mimicked both by the alpha(2) adrenergic agonist, clonidine (18/28, 64%) and the beta adrenergic agonist, isoproterenol (9/24, 38%). NA-induced hyperpolarizing effect was also blocked by the alpha(2) adrenergic antagonist, yohimbine in five out of six neurons tested. However, a minority (5/71, 7%) of neurons tested were depolarized by NA, and these depolarizing effects were mimicked by the alpha(1) adrenergic agonist, phenylephrine (11/26, 42%). NA-induced hyperpolarizing effects were maintained in the presence of tetrodotoxin (TTX), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), d,l-2-amino-5-phosphonopentanoic acid (AP5), picrotoxin and strychnine, a Na(+) channel, ionotropic glutamate receptor, GABA(A) and glycine receptor antagonists, respectively, indicating that the effects of NA are direct on the postsynaptic SG neurons. These results indicate that alpha(2) and beta adrenoceptor mediate inhibition, and alpha(1) adrenoceptor mediates facilitation of orofacial nociceptive processing in mouse trigeminal brainstem SG neurons by postsynaptic actions.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
17110030
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"