Effects of intracerebroventricular injections of 2-deoxy-D-glucose,d-glucose and xylose on operant feeding in pigs

The effects, on operant feeding, of injection into the lateral cerebral ventricle of 50 μmoles CaCl₂, 4 mmoles D-glucose, 2-deoxy-D-glucose (2DG) or xylose, or NaCl, have been studied in five pigs. All the sugars and CaCl₂ were given in 1 ml of normal saline. Each of the sugar solutions produced transient drinking. Only CaCl₂ and 2DG significantly increased food intake during the hour following injection. The results show that the mechanism by which the pig responds to intracerebroventricular 2DG is similar to that of the rat and different from that of the sheep.     

Degeneration and electron microscope analysis of the synaptic glomeruli in the lateral geniculate body

Summary Optic fibers of retinal origin terminate in the lateral geniculate body exclusively in the so called glomerular synapses. They can be recognized on the basis of their unusually large irregular mitochondria having very few cristae. In the cat the structure of the optic terminal profiles is rather dense. The majority of terminals in most glomeruli originate from axons of other source. Relatively large axon terminal profiles of unusually light structure cannot be brought to degeneration by any interference with extraneous pathways. From Golgi information it becomes obvious that they originate from local Golgi 2nd type neurons. Small rather dense axonal profiles of the glomeruli can occasionally be traced back by degeneration to the occipital cortex (parastriate), although most of the descending cortical afferents of the lateral geniculate body terminate outside the glomeruli on more proximal parts of the dendrites. — Axo-axonic synapses are very frequent. If an optic terminal is involved, it appears that by structural standards it is presynaptic to the non optic. As judged, however, from the numerous axoaxonic contacts persisting after enucleation, many of the contacts are established between non optic axon terminals. — The progress of secondary degeneration and particularly the removal from the glomeruli of degeneration fragments is unexpectedly rapid. — The possible functional significance of these findings, especially also with regards to presynaptic inhibition, is discussed.     

Neocortical and hippocampal EEG in normal and lateral hypothalamic-damaged rats

Cortical and hippocampal EEG were correlated with behavior in rats before and after bilateral hypothalamic (LH) damage. In Stage 1 of recovery (aphagia and adipsia), the neocortex showed continuous large amplitude slow activity. It did not desynchronize during spontaneous acts such as grooming as well as during tail pinch-induced struggling or orienting, even though a slow form of hippocampal theta accompanied these acts. However, during Stage 2 (anorexia), the neocortical EEG did desynchronize when such theta appeared. Therefore, as behavioral recovery progresses after LH damage, there appears to be a concomitant recovery of cortical participation in such behavior. Early in recovery, LH rats, unlike normals, showed slow (3–4.5 Hz) atropine-sensitive hippocampal theta during automatisms such as grooming as well as during immobility. Thus, LH damage, while temporarily abolishing fast. noncholinergic theta, appears to release slow cholinergic theta. Later in recovery, faster atropine-resistant (noncholinergic) theta becomes functional again.     

Dependence of the anterior olfactory area self-stimulation upon the lateral hypothalamic area

The functional relation between the anterior olfactory area (AO) and the lateral hypothalamic area (LH) was examined in a self-stimulation situation. Bar-pressing responses for AO sitmulation were suppressed by unilateral injection of procaine, and enhanced by glutamate, into LH. Neither procaine nor glutamate injected into AO had any influence upon LH self-stimulation. It is unlikely that the procaine effect was due to motor disturbance because similar injection of procaine into LH did not disturb the performance of a one-way avoidance task. It appears that the rewarding effect of AO stimulation is dependent upon the excitation of the more caudal structures including LH.     

Development of brain stimulation reward in the medial prefrontal cortex: Facilitation by prior electrical stimulation of the sulcal prefrontal cortex

Electrical stimulation of the medial prefrontal cortex (MC) in rats delivered daily for seven days causes a marked improvement in the rate of acquisition of a self-stimulation response. In the present experiment, we looked at whether we could get the same facilitatory effect on self-stimulation of the MC by delivering pre-training stimulation to other points in the brain anatomically related to the MC. Electrical stimulation of the lateral hypothalamus was without effect. However, electrical stimulation of the sulcal prefrontal cortex (SC) either contralateral or ipsilateral to the MC electrode did facilitate acquisition of self-stimulation of the MC. Thus the SC and MC would appear to be part of the same substrate controlling the development of positive reinforcement in the MC.     

Dopamine and serotonin: influences on male sexual behavior

Steroid hormones regulate sexual behavior primarily by slow, genomically mediated effects. These effects are realized, in part, by enhancing the processing of relevant sensory stimuli, altering the synthesis, release, and/or receptors for neurotransmitters in integrative areas, and increasing the responsiveness of appropriate motor outputs. Dopamine has facilitative effects on sexual motivation, copulatory proficiency, and genital reflexes. Dopamine in the nigrostriatal tract influences motor activity; in the mesolimbic tract it activates numerous motivated behaviors, including copulation; in the medial preoptic area (MPOA) it controls genital reflexes, copulatory patterns, and specifically sexual motivation. Testosterone increases nitric oxide synthase in the MPOA; nitric oxide increases basal and female-stimulated dopamine release, which in turn facilitates copulation and genital reflexes. Serotonin (5-HT) is primarily inhibitory, although stimulation of 5-HT(2C) receptors increases erections and inhibits ejaculation, whereas stimulation of 5-HT(1A) receptors has the opposite effects: facilitation of ejaculation and, in some circumstances, inhibition of erection. 5-HT is released in the anterior lateral hypothalamus at the time of ejaculation. Microinjections of selective serotonin reuptake inhibitors there delay the onset of copulation and delay ejaculation after copulation begins. One means for this inhibition is a decrease in dopamine release in the mesolimbic tract.     

Lateral actions at the inner plexiform layer of the carp retina: effects of turning windmill pattern stimulus

Lateral action from amacrine to ganglion cells was studied in the isolated carp retina by using a truncated windmill pattern (TWP). About 25% of ganglion cells of both "on" and "off" center types were suppressed or enhanced in firing activity in response to TWP turning. The suppressed cells were more sensitive to slow turning velocities of TWP than the enhanced cells. In the "on-off" type amacrine cells, a steady depolarizing or hyperpolarizing component (less than several mV) was maintained by stationary TWP, while the cells were exclusively depolarized by turning TWP at a wide range of velocities. These results suggest that individual responses of ganglion cells induced by both stationary and turning TWP are depending on a balance between two factors: the polarizing direction of steady components of the "on-off" amacrine cells and the polarizing direction of ganglion cells synaptically produced by the amacrine cells.     

Role of strengthening during nonoperative treatment of lateral epicondyle tendinopathy

IntroductionLateral epicondyle tendinopathy (LET) is the most common cause of lateral elbow pain. The literature on rehabilitation of the condition encompasses a plethora of interventions with most current evidence indicating that stretches and some form of strengthening are vital components. However, patient outcomes are infrequently reported further than 12 weeks from the start of therapy and it is unclear which components of a home exercise program are necessary to alleviate symptoms up to one year from the initiation of a therapy program.Purpose of the StudyThe purpose of the study is to determine if a therapy program with 4 to 6 visits spaced out over 12 weeks focusing on self-management and strengthening is more effective in reducing pain and improving function long term than the same program without strengthening, for individuals with LET.Study DesignThis is a randomized controlled trial.MethodsNinety-four patients were randomly allocated into two groups: both groups received the interventions of education in pertinent pathoanatomy, stretching, pain management through rest and icing, and activity modification. Group 1 (n = 38) was also provided with a strengthening component to the home exercise program, whereas group 2 did not (n = 21). Our primary outcome measure was pain at rest and pain with activity; our secondary measure was the level of functional impairment as measured by the quick disabilities of arm shoulder and hand. Outcome measurements were assessed at baseline, 6, 12, 24, and 52 weeks after initiation of therapy.ResultsBoth groups demonstrated statistically significant improvement with a moderate to large effect size in pain and function scores when compared with previous time point at 6, 12, and 24 weeks. Pain continued to decrease for both groups from 24 weeks to 52 weeks, but interestingly, there was a significant increase with moderate effect size in the quick disabilities of arm shoulder and hand score at 52 weeks when compared with week 24. No statistically significant difference was found between the two groups at any time point up to 52 weeks from the start of therapy.ConclusionsThis study demonstrates that a therapy program consisting of a low number of visits spaced out over 12 weeks based on education, stretches, activity modification, and pain management techniques is effective at reducing pain and increasing function in patients with LET. The addition of strengthening to this program did not improve outcomes. The therapy approach used in this study is consistent with the International Classification of Function guidelines and focuses on engaging patients in self-management of the condition through patient education and self-empowerment.