Electrical and chemical activation of the mesencephalic and subthalamic locomotor regions in freely moving rats

The locomotor activity of freely moving rats was increased by electrical stimulation of brainstem sites, including the pedunculopontine nucleus, a major component of the mesencephalic locomotor region (MLR), and sites located in the subthalamic locomotor region (SLR), which is in the area of the zona incerta (ZI) dorsomedial to the subthalamic nucleus. Injections to the MLR of glycine, an inhibitory transmitter of the spinal cord and brainstem, had no effect on locomotion, nor did strychnine sulfate, a glycine antagonist. Unilateral injections of the excitatory amino acid, N-methyl-D-aspartic acid (NMDA), and kainic acid, a glutamate analogue, into the MLR produced an increase in locomotion not seen with glutamate, an excitatory amino acid, into the same area. A still greater response, having a later onset than NMDA but also a longer duration, was produced by administration of picrotoxin and bicuculline methiodide, GABA antagonists, to the MLR. Carbachol injections into the MLR produced two types of responses: either increased or decreased locomotion. Hypermotility resulted from microinjections of glutamate, and picrotoxin and bicuculline, into the ZI. The short latency, short duration response to glutamate resulted in a greater increase in locomotion than with picrotoxin or bicuculline when each was administered into the SLR. These results provide further evidence for the functional role of the MLR and SLR in the initiation of locomotor activity in the intact, freely behaving rat.     

Age-matching improves the results of renal transplantation with older donors

Whilst HLA matching is routine for renal transplantation, the possible benefits of matching donor and recipient age have not been previously examined. In this study we examined the simultaneous effect of donor to recipient age difference on the graft survival of 141 consecutive first cadaver transplant recipients treated by cyclosporin immunosuppression. Multivariate regression analysis, taking into account other variables of moderately matched recipients (i.e. dialysis time and type, donor/recipient sex, local/imported kidneys, recent sensitivity, total ischaemic time, preoperative transfusions), indicated that age-difference was the single most important variable (P less than 0.05). Individually there was no significant effect of recipient age, whilst older donors (aged greater than 50 years) were associated with significantly worse graft survival than those younger (P less than 0.01). When dealing with donors aged greater than or equal to 50 years the corresponding recipient 1-year graft was improved when the donor was no more than 5 years older than the transplant recipient. Donor age to recipient age difference is a potentially important selection criterion in renal transplantation.     

Glutamate immunoreactive terminals in the lateral amygdaloid nucleus: a possible substrate for emotional memory.

The ultrastructure and synaptic associations of terminals immunoreactive for L-glutamate (Glu) were examined in the lateral nucleus of the amygdala (AL). All results reported here involved tissue fixed only with paraformaldehyde. The specificity of the antiserum with paraformaldehyde fixation conditions was assessed and confirmed by immuno-dot blot analysis: the reactivity of anti-Glu to glutamic acid was at least 1,000 times greater than the reactivity to other amino acids. At the light microscopic level, Glu-immunoreactive punctate processes and somata were present in AL. At the electron microscopic level, many Glu-immunoreactive terminals were identified. Data analysis was performed on 365 of these labeled terminals. Glu-immunoreactive terminals were 0.3-1.5 microns in diameter and contained numerous small, clear vesicles as well as mitochondria. Many (77%) of the terminals analyzed had morphologically identifiable synaptic specializations. Most (90%) of the Glu-immunoreactive terminals with synaptic specializations formed asymmetric synapses on spines or small dendrites; synaptic specializations on soma or proximal dendrites were rarely seen (< 1%). Glu-immunoreactive terminals were qualitatively compared to terminals in AL labeled with two other antisera: anti-glutaminase, a marker for the enzyme that catalyzes the conversion of glutamine to the releasable or transmitter form of Glu, and anti-gamma-aminobutyric acid (anti-GABA), a marker for the major inhibitory amino acid transmitter in the brain. Terminals immunoreactive for glutaminase, like those immunoreactive for Glu, formed mostly asymmetric synaptic specializations on spines or small dendrites. In contrast, GABA-immunoreactive terminals usually formed symmetric synapses on soma or proximal dendrites and were never observed to form asymmetric axo-spinous contacts. Although Glu is a metabolic precursor to GABA, these data indicate that the majority of Glu-immunoreactive terminals reflect the site of synthesis and release of Glu and not of GABA. In addition, these results provide morphological evidence that Glu plays a role in excitatory neurotransmission at synapses in AL and support the growing body of data implicating excitatory amino acid-mediated synaptic plasticity in-emotional learning and memory processes in AL.     

Distribution of selenium in human milk

The present studies were designed to characterize selenium distribution in human milk. These studies reveal that most selenium in human milk is protein bound. Percentage dialyzable selenium varied proportionally with total selenium content of milk but not with stage of lactation. Neither rate of freezing nor frozen storage of samples for one month influenced distribution profiles. At least nine selenoproteins were detected in dialyzed milk samples following molecular sieve (Sephadex) chromatography. Glutathione peroxidase accounted for approximately 15-30% of selenium found in milk. Approximately half of peroxidase activity in human milk was associated with selenium dependent glutathione peroxidase activity.     

A disorder of lightness discrimination in a case of visual form agnosia

Benson and Greenberg (1969) described an "agnosic" patient whose severe visual recognition disorder could be accounted for in terms of a deficit in the perception of shape. We report here on a recent case of this disorder (visual form agnosia), and have found that she performs very poorly on tasks of discriminating shades of grey, although she is able to discriminate between hues. This sensory deficit helps to explain some of her perceptual difficulties; it also provides further evidence for parallel feature-processing in the human brain complementary to and consistent with recent physiological data on the visual cortex in animals.     

Location of the gene for 21-hydroxylase deficiency.

HLA typing of 33 families with one or more children suffering from congenital adrenal hyperplasia confirmed that the gene for 21-hydroxylase deficiency is closely associated with the HLA region. Analysis of two families in which recombination of chromosome 6 had occurred indicated that the gene locus is between the A and D loci of the HLA region. The rare allele Bw47 was observed in 18 parents and was always associated with the carrier state for 21-hydroxylase deficiency.