Influence of neurotransplantation on rats'' behavior with different conditions of reinforcement

Recently, we have reported a marked rat lateralization in the T-maze choice. Embryonic rat tissue from neocortex, hippocampus, hypothalamus and amygdala was transplanted into intact rat brains in various combinations: 1) neocortex and hypothalamus (Neo + Hyp); 2) hippocampus and amygdala (Hipp + Amyg); 3) neocortex and hippocampus (Neo + Hipp); and 4) hypothalamus and amygdala (Hyp + Amyg). Once under conditions in which reinforcement was equally qualitative and equally probable, rats in all groups chose the T-maze arm contralateral to the side of implantation. In a second set of experiments, rats were presented a choice between quality and probability of reinforcement. The right arm of the T-maze contained a cup of water 33% of the time (high-quality but low-probability reinforcement). The left sleeve contained a solution of 0.15% quinine in water 100% of the time (low quality but high probability of reinforcement). Rats that received Neo + Hyp transplants chose the T-maze arm that always contained a drink cup with water significantly more often than they chose the arm that always contained the drink cup with quinine solution. Rats that received Hipp + Amyg transplants chose the arm containing the drink cup with quinine solution much more often than the arm that sometimes contained a cup of water. Rats with transplanted Neo + Hyp generally were more active than rats with transplanted Hipp + Amyg. These data suggest that the behavior of rats can be affected by selective transplantation of different brain tissue.     

Studies of the Effects of Monoamines on Orexinergic Neurons in the Hypothalamus of Rat Embryos

Neuroscience and Behavioral Physiology - Hypothalamic orexinergic neurons are involved in controlling various body functions, particularly energy balance, feeding behavior, wakefulness, and...     

Chronic renal failure in middle-aged and elderly persons

The authors analyzed the frequency of chronic renal insufficiency (CRI) and the level of serum creatinine (200 mumol/l and more) in 10,350 outpatients aged over 60 (I group), 2400 persons of the same age in need of episodic hospitalization (II group), and in 1840 patients who died in hospital (III group). In the 1st group CRI frequency was 0.98%, in the 2nd group--6.9%, in the 3rd group--14.6%. Pyelonephritis (76.1%) and myelonephropathy (7.5%) were among CRI main causes. The authors underlined the multitude of factors causing CRI in middle-aged patients and the prospects of adequate therapy even in terminal states; CRI syndromes were considered for persons of this age group.     

Stereotaxic investigation of the lateral horn of the cat spinal cord

Coordinates of the lateral horn in segments C8-L3 were measured in specimens of the cat spinal cord, using the point of entry of the dorsal root as reference point. When choosing coordinates, various methods of orientation of the microelectrode used to test sympathetic preganglionic neurons (SPGNs) were considered. Electrophysiological investigation of SPGNs showed that the coordinates described here ensured correct placing of the microelectrode in the lateral horn. Determination of recording points suggests a compact arrangement of SPGNs in the dorsal part of the lateral horn. Slower conduction of antidromic excitation along the intramedullary part of the SPGN axons than along the peripheral part, detected by electrophysiological experiments, suggests that the axon of these neurons has a long, thin, nonmyelinated part.