Effect of menstrual cycle phase on dopamine D2 receptor availability in female cynomolgus monkeys

Sex differences have been reported in a variety of affective and neurodegenerative disorders that involve dysfunctional dopamine (DA) neurotransmission. In addition, there is evidence for differences in sensitivity to the abuse-related effects of psychostimulants across the menstrual cycle which may result from effects of ovarian hormones on DA function. The goal of the present study was to extend previous work examining menstrual cycle-related changes in DA D2 receptor availability in humans to drug-naive female cynomolgus monkeys (n=7) using the selective D2-like receptor ligand [(18)F]fluoroclebopride (FCP) and a high-resolution microPET P4 scanner. Menstrual cycle phase was characterized by daily vaginal swabs and measurements of serum progesterone levels. PET studies were conducted once during the luteal phase and once during the follicular phase. Regions of interest in the caudate nucleus, putamen, and cerebellum were defined on coregistered MRIs. Distribution volumes were calculated for FCP in each structure and the distribution volume ratio (DVR) for both brain regions relative to the cerebellum was used as a measure of D2 receptor availability. FCP DVRs were significantly higher in the luteal phase compared to the follicular phase in both the caudate nucleus (11.7% difference, p=0.02) and putamen (11.6% difference, p=0.03). These findings extend earlier work in humans and suggest that changes in DA receptor availability may be involved in the variation in symptoms of various neuropsychiatric disorders across the menstrual cycle, including differences in sensitivity to the abuse-related effects of stimulants.     

Surgical sepsis. Diagnostic criterions

Possibilities of timely diagnosis of sepsis were discussed. Informativity of its clinical symptoms, laboratory and instrumental data was studied. Diagnostic criteria were formulated, the programme of complex diagnosis of sepsis was suggested.     

Characteristics of the formation of systems activity in the brain and autonomic functions in children in conditions of the European North (discussion paper)

Results obtained from complex medical-physiological investigations performed during 10 scientific expeditions in the Arkhangel’sk Region in 2003–2005 are presented. The effects of climatological-geographic, biogeochemical, and social conditions of the conditions obtaining in the Far North region of Russia on sexual maturation, formation of the structural-functional organization of the brain, autonomic functions, and immunological and biochemical status of schoolchildren were studied using state-of-the-art neurophysiological methods (computerized electroencephalography, computerized rheoencephalography, computerized electric dipole origin tomography, etc.), psychophysiological and psychometric methods (assessment of the state of cognitive and memory functions, Wechsler intellectual scale), along with biochemical assay of monoamine oxidase (MAO, the key enzyme in adrenergic neurotransmitter metabolism) and the liver enzyme butyrylcholinesterase (BuChE) and physicochemical analysis of the levels of macroelements and trace elements in the body. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 92, No. 8, pp. 905–929, August, 2006.