Neonatal Cats Research Articles

A sensitive myelin-sheath stain particularly useful for small mammals and neonatal cats.

Staining of myelinated fibers including the delicate myelin sheaths of infantile animals is as follows: perfuse the anesthetized animal with a pH 7.4 posphate-buffered fixative, either 10% formalin, 6% gluteraldehyde or a mixture containing 3% gluteraldehyde and 2% acrolein. Dissect out the brain or spinal cord and continue fixation for at least 24 hr. Cut larger brains to 1 cm in at least one dimension. Wash in running tap water 2-3 hr and soak in 2.5% potassium dichromate in 1% acetic acid (the primary mordant) for 3-5 days in darkness. Wash at least 12 hr in running tap water. Dehydrate and embed in celloidin and store in 80% ethanol. Section at 25-60 μ into 80% ethanol. Wash 1-2 min in distilled water and then immerse in 1-2% ferric alum at 50 C for at least 1 hr (the secondary mordant). Wash in tap water and stain at least 1 hr at 50-60 C in 0.5% unripened hematoxylin in 1% acetic acid. Wash well in tap water and differentiate in a mixture containing 0.5% ferrityanide, 0.5% borax and 0.5% Na2CO3; 2 c...

Sparing of photic frequency and brightness discriminations after striatectomy in neonatal cats.

Sparing of photic frequency and brightness discriminations after striatectomy in neonatal cats.

Development of cortical neuronal activity in the neonatal cat

The development of spontaneous activity and of responses to flash has been studied in single neurons of marginal gyrus in kittens from birth to age 8 weeks. No spontaneous or evoked activity was found in cortical neurons in the immediate neonatal period. In subcortical fibers, spontaneous activity was present already at birth. The first recordable spontaneous activity in cortical neurons consisted of brief, synchronous bursts, followed by prolonged periods of silence. Maturational changes in spontaneous neuronal activity consisted of a decrease in synchrony of neuronal discharges, an increase in rate of spontaneous discharges, and the appearance of tonic discharges in a large number of cortical neurons. Flash responses in cortical neurons were prominent in the more immature animals, but diminished as maturation progressed.

Characteristics of blood-brain barrier to gamma-aminobutyric acid in neonatal cat.

Systemic gamma-aminobutyric acid produces a rapid, sustained, but transiently reversible blockade of evoked axodendritic excitatory postsynaptic potentials in neonatal cortex when the "barrier" operating to restrict its passage has been altered by various experimental procedures. The data obtained under these conditions indicate the existence of well-developed synaptic pathways in the superficial neuropil of immature cortex.

OPTIC NERVE REGENERATION WITH RETURN OF VISION IN ANURANS

OPTIC NERVE REGENERATION WITH RETURN OF VISION IN ANURANS