Sexual differentiation of the central nervous system

Sexual differentiation of reproductive and behavior patterns is largely effected by hormones produced by the gonads. In many higher vertebrates, an integral part of this process is the induction of permanent and essentially irreversible sex differences in central nervous function, in response to gonadal hormones secreted early in development.     

Axons: isolation from mammalian central nervous system

Centrifugation of a homogenate of white matter, in a solution of buffered sucrose containing salt, produces a floating layer of myelinated axons. When these are suspended in hypotonic buffer, the mnyelin swells and strips away from the axon. Axons are then separated from the myelin by centrifugation. The resulting preparation consists of a variable population of processes with lengths up to 200 micrometers and diameters between 0.3 and 5.0 micrometers. The axons contain neurofilaments and mitochondria, although no axolemma or neurotubules are evident. The preparation contains cerebroside and sulfatide, yet is essentially free of myelin.     

Retrograde axonal transport in the central nervous system

When horseradish peroxidase is injected into the optic tectum of a chick, axons of ganglion cells transport it centripetally to their cell bodies in the retina at a rate of about 72 millimeters per day. After intraocular injections in the young chick, the peroxidase is transported centripetally along efferent axons, and is concentrated in cell bodies within the isthmo-optic nucleus. This retrograde movement of protein from axon terminal to cell body suggests a possible mechanism by which neurons respond to their target areas.     

Transneuronal transfer of radioactivity in the central nervous system

After injection of tritiated amino acid into the mouse eye, radioactivity appeared in the contralateral visual cortex, indicating that some material had been transferred from optic axons to lateral geniculate neurons. The radioactivity in the cortex was about 2 percent of that arriving in the geniculate, and most of it was contained in material that appeared to be protein.     

Neuroscience. Stout guards of the central nervous system

Endocannabinoids have paradoxical effects on the mammalian nervous system: Sometimes they block neuronal excitability and other times they augment it. In their Perspective, Mechoulam and Lichtman discuss new work (Marsicano et al.) showing that activation of the cannabinoid receptor CB1 by the endocannabinoid anandamide protects against excitotoxic damage in a mouse model of kainic acid-induced epilepsy.     

Immunobiological properties of reovirus type I

This paper studies the cultural, haemagglutinating, physicochemical, antigenic, and pathogenic properties of reovirus type I (strain Reo I Lang). It was shown that the strain Reo I Lang of reovirus type I corresponds to the criteria characterizing the family Reoviridae, genus Ortoreovirus, and can be used as a production one when developing diagnostic and prophylactic preparations.     

Immunocytochemical detection of acetylcholine in the rat central nervous system

A specific antibody to acetylcholine was raised and used as a marker for cholinergic neurons in the rat central nervous system. The acetylcholine conjugate was obtained by a two-step immunogen synthesis procedure. An enzyme-linked immunosorbent assay was used to test the specificity and affinity of the antibody in vitro; the results indicated high affinity. A chemical perfusion mixture of allyl alcohol and glutaraldehyde was used to fix the acetylcholine in the nervous tissue. Peroxidase-antiperoxidase immunocytochemistry showed many acetylcholine-immunoreactive cells and fibers in sections from the medial septum region.     

Axonal elongation into peripheral nervous system "bridges" after central nervous system injury in adult rats

The origin, termination, and length of axonal growth after focal central nervous system injury was examined in adult rats by means of a new experimental model. When peripheral nerve segments were used as "bridges" between the medulla and spinal cord, axons from neurons at both these levels grew approximately 30 millimeters. The regenerative potential of these central neurons seems to be expressed when the central nervous system glial environment is changed to that of the peripheral nervous system.     

Habituation and dishabituation in the absence of a central nervous system

Habituation and dishabituation have been observed in a semi-intact Aplysia preparation in which the central nervous system is removed. The amplitude of withdrawal responses in the gill decreases in proportion to the rate of water drops applied (one drop per 0.5 minute to one drop per 2.5 minutes at 15 degrees C). The effects of habituation last for at least 2 hours. A dishabituated response is elicited by stopping the water drops or electrically stimulating the preparation. Furthermore, the gill contains nerve cell bodies, and habituation and dishabituation appear to be properties of these peripheral neurons.     

黄病毒入侵中枢神经系统的分子机制研究进展

临床上黄病毒可以引起中枢神经系统(central nervous system,CNS)疾病,易造成神经系统的后遗症.黄病毒可以通过血源性途径、特洛伊木马途径和神经轴突转运的方式跨越血脑屏障(blood brain barrier,BBB).病毒穿越BBB进入CNS后,被病毒激活的内皮细胞、胶质细胞和神经细胞会释放大量...     

Botulinus toxin: effect on the central nervous system of man

Electrical stimulation of multiple peripheral nerves, elicited "H" reflexes in a patient, 61 years old, with botulism. These reflexes are extremely suggestive of some central release or failure of inhibitory control of a monosynaptic or polysynaptic spinal reflex arc. This "central" action of botulinus toxin is similar to that suggested for tetanus toxin.     

Poliovirus inhibitor from the central nervous system of the Rhesus monkey

The production of riboflavin by Eremothecium ashbyii is appreciably reduced by 3-amino-1,2,4-triazole at concentrations of inhibitor which do not inhibit growth. Corn and pea leaf tissues which are albinistic as a consequence of treatment with this compound have a greatly lowered riboflavin content.     

Property of cerebrospinal fluid associated with disturbed metabolism of central nervous system

Cerebrospinal fluid was assayed for the capacity to contract smooth muscle and for the capacity to develop such activity when incubated with globulin. Activity was observed in fluid collected from patients with inflammatory or degenerative disease of the central nervous system, sustained intracranial vasodilatation, sustained noxious stimulation, or chronic schizophrenia. Control specimens lacked measurable activity.