96

.;~.h chronic pain syndromes yields 7 factors. Four were composed of personality measur,-.'s, two inv,Aved different psychophysical pain measares, and one involved a sex-re:ated factor. 'me clxiet" factors, comprising more than 50 ~(. ~f the total variance, were interpersonal alienation and man!pulativeness', 'clinical pain intensky', and "pain ,~ndurance'.

.a, na~ges~a produced t)y brfiin stimulation: ~vidence Gf a prolonged onse:. period

R. Melzack and D. F. Melinkoff, £xp. Neurol., 43 (1974) 369-374

The onset of analgesia elicited by electrical stimalation of sites in the midbrain reticular for:nation was studied in cats, using an experimentally produced pain that provides a measureable index c f perceived pain ~ntensit3;. The results showed that the analge...ia develops gradually o~c;: a period of about 5 rain or longer. This period may be due to the time required for r.~cruitment o ;a critical number &active r.eurons, or to the release ofa neurochemical agent which requires time ~o exert its effects on adjacent neurons or at more distant neural areas.

Beha,~ioral and electrophy,3io...~gicai evidence of pain inhibition from midhrain stim,da~;on

J. L. Ollveras, J. ~/I. Besson, G. Gailbaad and J, C. Liebeskin0, Exp. Brain Res., 20 ¢ 197~.~ 32-44

M~dbrain st initiation by chrcnically implanted electrodes in a~ake cats in the vici~l=ty of dorsal raphe nucleus ew)ked profound analgesia ~,o ?eripherally applied noxiou~ stimuli~ ,.tot accc, mpani,'d by ~th:: obvious sensory or mt)tor deficits. 'fhe perilz.heral field of analgesi~, sometimes 'included the entire body and in other cases was restricted to the hindquarters.. Analgesia generally outlasted I~rain stimulation by no more t aan 10 .sec. Stimulatien distant from dorsal raphe led to pronounced motor or emotional effeczs precluding an ad:::~uate test of analgesia. In anesthetized cats, effects c f r,',idbrain stimulation were ,;tudie5 on evoked activity in dorsal horn lamina 4 and 5 ce!ls. Stimulatie.t of wide ::egions of raidbra[n inhibited 'pain-evoked' activity in most Hmina 5 cells wi:hout affecting responses of most lamina 4 cells. In some lamina 5 cells, midbrain ,,,timulathm inhibited responses ~.o noxious but not innocuous stimuii.

PSYCH. ATRY

~e~sis.f:on~ ana!gesic abt.'se in analgesic, nephropathy

R. M. Murray, & Psychosom. Res., t 5 (1977.'~ 5;:'-62

It !'.,as been widely recognised that thor,: h ~ been a hi~-h incidence of psychiatric