Torsten Åkesson

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The ventromedial nucleus of the hypothalamus (VMH) plays a crucial role in the mediation of lordosis by integrating predominantly inhibitory limbic signals with cyclic variation of ovarian steroids and sending a stimulatory output to the midbrain, especially the periaqueductal gray (PAG). Tract-tracing studies have established projections of the VMH and(More)
The hypothalamic distribution of cholecystokinin-immunoreactive (CCKI) cell bodies in colchicine-treated male and female rats was studied. Immunoreactive neurons were visualized along the anterior two-thirds of the third ventricle but were especially numerous in the preoptic periventricular nucleus. Dense aggregations of CCKI cells were found in the(More)
Midbrain control of vocalization was evaluated in the ring dove by determining the major afferent inputs with retrograde tract tracing technique. Horseradish peroxidase was infused into various portions of the nucleus intercollicularis, an estrogen concentrating area, which disrupts nest calls when lesioned and induces the vocalization when stimulated by(More)
The distribution of cholecystokinin-immunoreactive (CCK-I) cell bodies was studied in the bed nucleus of the stria terminalis (BST) and amygdaloid complex of colchicine-treated male and female rats. Immunoreactive cells were visualized in the BST medial amygdaloid (MeA), central lateral, basolateral, basolateral ventral, medial, intercalated, anterior(More)
Male and female rats have approximately equal numbers of estrogen(E)-concentrating cells within the medial preoptic area (MPOA). Several cell groups within this brain region are sexually dimorphic, however, and these groups may have sexually different numbers of E-containing cells; this, in turn, may reflect sex differences in neural-regulated functions. In(More)
Substance P has been implicated in the modulation of lordosis behavior at the level of the dorsal midbrain central gray (dMCG). Bilateral injections of substance P into the dMCG facilitate estrogen-induced lordosis behavior in ovariectomized female rats. Input from the ventromedial nucleus of the hypothalamus (VMH) to the dMCG is a vital link in the central(More)
Nest-coo (courtship) vocalization is an estrogen-dependent component of a sequence of behaviors leading to egg-laying in the ring dove (Streptopelia risoria). Implantation of estrogen in the nucleus intercollicularis of ovariectomized females restores the ability to produce nest-coos. Lesion of n. intercollicularis specifically disrupts nest-cooing and(More)
The ventromedial nucleus of the hypothalamus (VMH) is an important site in the mediation of female receptive behavior (lordosis); however, the sequence of events that eventually facilitate this estrogen-dependent behavior is only partially understood. Here, evidence is presented, suggesting that an interaction between gonadal steroids and tachykinin(More)