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Biomedical subjects

P P Bateson

Publications and source records attributed to P P Bateson.

At least 19 recordsLinked to original sources

Rules and reciprocity in behavioural development: implications for rehabilitation.

This article considers the potential value of two bodies of thought arising from work on animals in connection with rehabilitating abnormal behaviour. One deals with the processes of catch-up and self-regulation, and the other with optimal periods of learning in development. The ideas about self-regulation are important because an individual with abnormal behaviour at one stage in development may cease to be abnormal of its own accord. The sensitive period concept in development has often been seen as being opposed to that of possible adult rehabilitation. Much of the animal evidence suggests that the opposition is false.

Animals↗

Effects of restricted lesions of the chick forebrain on the acquisition of filial preferences during imprinting.

The effects of placing bilateral lesions in that part of the chick brain (IMHV) which was previously been implicated in imprinting, was studied in young domestic chicks. Twenty-four dark-reared chicks were matched in pairs on the basis of their approach activity during a 30 min period of exposure to one of two visual imprinting stimuli. Both members of the chick pair were then anaesthetized and bilateral lesions were made by radio-frequency coagulation in the IMHV of one chick; the other chick served as a sham-operated control. On the following day each chick was exposed for 2.5 h to the imprinting stimulus to which it had previously been exposed. After training, the preferences of all chicks were measured by comparing their approach to the training stimulus with that to the second stimulus. Sham-operated chicks showed a strong preference for the training stimulus; lesioned chicks showed none. Subsequently the latency of each chick to approach and accurately peck a shiny rod was measured. The two groups of chicks did not differ significantly in this test of visuomotor coordination. The area of tissue damaged by the lesion was reconstructed: IMHV was severely damaged with relatively little damage to other areas of the brain.

Animals↗

An autoradiographic study of the chick brain after imprinting.

On the first day after hatching domestic chicks were exposed to an imprinting stimulus, a horizontal yellow slit of light moving upwards in a window and presented at a rate of 4 slits/sec. Chicks were exposed for either 45 min (undertrained) or 180 min (overtrained) on the first day of hatching (60 or 240 min in the case of 1 pair). On the second day all birds were exposed for a further 63 min. Twenty birds were matched in pairs and each chick received 1.1 muCi [14C]uracil/g body weight injected into the heart region before exposure on day 2. At 150 min after the injection the chicks were decapitated and serial coronal sections of their brains cut; alternate pairs of sections were prepared for autoradiography. The optical density for a number of major anatomical regions was measured. The measurements for each region were averaged over congruent to 0.6 mm 'slabs' of brain and expressed as a percentage of the mean of all measurements for that brain. Standardized mean optical density was significantly greater in undertrained chicks than in overtrained chicks in a part of the medial region of hyperstriatum ventrale (MHV) which extended across two adjacent slabs. The slabs were slightly posterior to the mid-point between anterior and posterior poles of the brain. In the next two, adjacent, anterior slabs the variances for MHV were significantly greater in undertrained chicks than in overtrained chicks. There were no other significant differences between brain regions. Taken together with previous studies these results suggest that the intermediate and medial part of hyperstriatum ventrale is intimately linked with the imprinting process.

Animals↗

Effects of rhythmic hyperstriatal stimulation on chicks' preferences for visual flicker.

Chicks' preferences for the frequency of a flashing light can be modified by electrically stimulating the medial part of the hyperstriatum ventrale with trains of shocks at that frequency. Chicks stimulated with 1.5 pulse trains s-1 preferred a light flashing at 1.5 s-1 and chicks stimulated at 4.5 trains s-1 preferred a light flashing at 4.5 s-1. Three behavioural measures taken during the preference test, namely measures of movement, latency to approach and distress calls were not significantly influenced by the frequency of brain stimulation.

Animals↗

Effects of imprinting on lysine uptake and incorporation into protein in chick brain.

One-day old chicks were exposed for either 30, 60, or 120 min to an imprinting stimulus or kept in darkness in similar conditions. At the end of this time they were injected peripherally with 14C-lysine and killed 20 min later. The radioactivity of free lysine and that incorporated into protein was measured; incorporation was found to differ between exposed and dark birds only in the anterior part of the forebrain roof after 60-min treatment (E/D = 1.25). However, more free radioactive lysine was found in all brain regions of exposed birds at this time. When the specific radioactivity of the free lysine (dpm/nmol lysine) was measured there were no differences between the two types of birds, indicating that the incorporation difference was not due to a change in precursor radioactivity. The use of 14C-2-aminoisobutyrate confirmed that even with a nonincorporated amino acid pool size changes still occurred. The greater lysine incorporation in anterior forebrain roof was largely restricted to the cytoplasmic soluble fraction.

Aminoisobutyric Acids↗

Imprinting: correlations between behaviour and incorporation of (14-C) uracil into chick brain.

On the first day after hatching 106 domestic chicks were injected with (14-C)uracil and exposed to a yellow or a red rotating flashing light for 72 min. Shortly before they were killed and 115 min after injection they were given a choice between the two lights. Incorporation of the (14-C)uracil into 4 regions of the brain was measured. Differences between batches and between training conditions were eliminated as sources of variation by standardising the behavioural and biochemical measures. Correlations between the measures were obtained. Chicks that were active from the early stages of training showed lower rates of incorporation in the midbrain, forebrain base and anterior of roof of the forebrain, than less responsive chicks. When the general lowering effect of behavioural activity on incorporation was eliminated as a source of variations, a striking positive correlation emerged between the preference for the familiar object and incorporation in the anterior of forebrain roof. Since preference for the familiar is a direct measure of imprinting and since no other behavioural measure is positively correlated with biochemical changes in anterior roof, it is concluded that these biochemical changes were closely linked with the learning process.

Animals↗

Imprinting: lasting effects on uracil incorporation into chick brain.

On the first day after hatching, domestic chicks were trained for 20, 60, 120, or 240 minutes with an imprinting stimulus. On the second day, they were all retrained for 60 minutes. The greater the chicks' experience on the first day, the lower the rate of incorporation of tritiated uracil into macromolecules in the anterior part of the forebrain roof on the second day. Such effects were not found in other brain regions, nor in any brain region of chicks that received similar treatment on the first day but were not retrained on the second.

Animals↗