Neural connection

The distribution of rods and cones is shown in Figure 3b centered about the fovea, the area of the retina that has the highest concentration of cones with essentially no rods and also has the best resolving capabiUty, with a resolution about one minute of arc. The fovea is nominally taken as a 5° zone, with its central 1° zone designated the foveola. There are about 40 R and 20 G cones for each B cone in the eye as a whole, whereas in the fovea there are almost no B cones. A result of this is that color perception depends on the angle of the cone of light received by the eye. The extremely complex chemistry involved in the stimulation of opsin molecules, such as the rhodopsin of the rods, and the neural connections in the retinal pathway are well covered in Reference 21. 

The precise mechanism through which benzodiazepines and barbiturates produce mood elevation remains to be elucidated. The mood-elevating effect of the benzodiazepines and barbiturates is probably mediated not only by acute increases in the actions of GABA but also by neural connections from... 

Delville Y., De Vries G.J. and Ferris C.F. (2000). Neural connections of the anterior hypothalamus and agonistic behavior in golden hamsters. Brain Behav Evol 55, 53-76. 

Salazar I., Barber P.C. and Cifuentes J.M. (1992). Anatomical and immuno-histological demonstration of the primary neural connections of the vomeronasal organ in the dog. Anat Rec 233, 309-313. 

The majority of neural connections in the human brain and spinal cord are characterized as chemical... 

Glucose sensitive neurons are present in the hypothalamus. They depend on glucokinase and act in many ways similar to beta cells [51]. They influence both insulin secretion and glucose uptake, and there appear to be neural connections between all glucose sensing cells [15]. The output may be part of the hepato-portal system, but also conditioned reflexes may participate in the neural stimulation of insulin release and glucose uptake [52]. In this sense the CNS also participates in predictive control. 

The effects of DBS on the cortex-basal-ganglia-thalamus-cortex motor loop appear to be more complex than initially believed. The paradox of DBS is that electrical stimulation of brain tissue (which presumably induces brain activation), has a similar effect as that of a surgical lesion of that same structure (which effectively destroys brain tissue). These two realities are hard to reconcile. As indicated by [64] the ultimate elucidation of this paradox depends on the nature of the complex and interactive neural connections in the brain that communicate through electrical and chemical processes. There is an emerging view that DBS has both excitatory and inhibitory effects on how brain circuits communicate with one another depending on the distance from the electrode, the cell structures activated and the direction of the activation (ortho- versus anti-dromic). The effect appears to modulate the activity of a network as well as neural firing patterns. Long term effects on neurotransmitters and receptor systems cannot be excluded [64]. 

Read for reinforcement and future needs. Even if you only have 10 minutes, put your notes or a book in your hand. Your mind is similar to a computer you have to input data in order to have it processed. By reading, you are creating the neural connections for future retrieval. The more times you read something, the more you reinforce the learning of ideas. 

Chevy Chase Howard Hughes Medical Institute, 1995. Purves, Dale. Body and Brain A Trophic Theory of Neural Connections. Cambridge Harvard University Press, 1988. Raven, Peter H., and George B. Johnson. Biology. 3rded. St. 

NMDA receptors—Specific neuron receptors that strengthen neural connections and may play a role in pain perception. 

The organization of the endocrine system can best be described in relation to the central nervous system. Three levels of endocrine tissues can be distinguished on the basis of their association with the central nervous system (Figure 30-12). The first level consists of those that are (or were) derived from nerve cells these include the hypothalamus, adrenal medulla, thyroid C-cell, and gastrointestinal enterochromaffin cells. The hypothalamus and adrenal medulla still retain their neural connections and can therefore be regarded as endocrine extensions of the nervous system. The C-cell and the gut cells, however, are APUD cells and lack neural connections. These four tissues produce hormonal peptides or amines having, like neurotransmitters, rapid-onset, short-term effects. 

Neural connections project information from taste receptors in the taste buds of the mouth, via cranial nerves VII and IX, and from nutrient sensors in the gastrointestinal (Gl) tract, via cranial nerve X. The nutrient sensors of the Gl tract may be activated by cholecystokinin (CCK) or serotonin (5-HT). The afferent fibers end at the nucleus of the solitary tract in the brainstem. From there, after integration with other signals, projections to the forebrain carry the sensory information to higher structures... 

Heimer, L. and Wilson, R.D. (1975) The subcortical projections of the allocortex Similarities in the neural connections of the hippocampus, the piriform cortex, and the neocortex. In M. Santini (Ed.), Perspectives in Neurobiology, pp.177-193. Raven Press, New York. 

The posterior pituitary gland secretes two hormones, antidiuretic hormone (ADH) and oxytocin. They are both synthesized in the hypothalamus and reach the posterior pituitary via a neural connection. See Figure 6.2. 

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