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Projections from different visual areas of the cerebral cortex to the ipsilateral claustrum have been investigated in the cat by intracortical injections of [3H]proline. As a consequence of axonal flow an accumulation of radioactive material within a dorso-caudal region of the ipsilateral claustrum was found. The proline-transporting terminal arborizations of projections from areas 17, 18, 19 and the Clare-Bishop area overlap in the same claustral region. No point-to-point relation was observed between any one visual area and its claustral projection. Differences in the terminal distribution pattern were detectable according to the visual areas of origin.

Solutions of tritiated aminoacids were injected into the visual cortical region hidden in the depth of the superior temporal sulcus (STs) of the macaque monkey. Injection sites involved the middle temporal visual area, extending into the surrounding visual cortices. Projections were found homolaterally in both the striatum and claustrum. In the caudate nucleus labeled material affected mainly the body and spread both to the tail and the head of the nucleus. Label was also seen in the caudal third of the putamen and in the postero-ventral claustrum. Compared with the scarcity of afferents arising from occipital visual areas, the present data point to a heavy projection system from additional visual areas of the STs to the basal ganglia in the macaque monkey.

Associated and commisural connections of visual areas 17 and 18 were studied in the light of the latest knowledge about the anatomo-functional organization of the cat's visual cortices. Injections of L-[5-3H] proline were placed, in different animals, in area 17 or 18 of the right hemisphere. Serial histological sections of the whole brain were processed by autoradiographic technique, after long (8-16 days) or short (30 hours) survival times. Cortical areas labelled by axonally transported radioactive material were then correlated with electrophysiological and cytoarchitectonical maps. Areas 17 and 18 were found to send associational projections to area 19, to the anterior and posterior subdivisions of the lateral suprasylvian visual area and to two regions lying on the crown of the suprasylvian gyrus (areas 21A and 20). In addition, area 18 sends projections to ipsilateral areas 17, 7 and 5. Contralaterally, projections from areas 17 and 18 reach the homonymous areas near the margin of the other. Homotopical callosal connections of area 17 affect the band of the contralateral 17 in which part of the ipsilateral visual hemi-field is represented. Heterotopical commisural projections from the areas studied affect areas 19 and LS in regions adjoining the central vertical meridian representations. These results suggest that, on an anatomical basis, the interactions between the cortical targets of the classical geniculo-striate and the estrageniculo-striate systems are more complicated than previously believed. Furthermore, the geniculo-striate system supplies some visual input to non-visual areas through area 18.

In II adult cats, areas 17, 18, 19 as well as the lateral suprasylvian area were separately injected with L-[5-3H] proline and their efferent projections to the frontal cortex were autoradiographically searched. Only area 19 and lateral suprasylvian area showed such projections; terminal sites were localized in the ventral and dorsal banks of the cruciate sulcus and in the adjacent mesial surface of the brain. The possibility that these labeled regions may correspond to the monkey's frontal eye field is discussed.

Thyroglobulin (Tg) levels were found to be elevated in 30 to 35 patients with euthyroid sporadic goiter and in 15 of 37 patients with euthyroid endemic goiter. The elevated Tg levels in the goitrous patients did not correlate with either goiter size, TSH levels, or urinary iodine excretion, but did correlate with the triiodothyronine to thyroxine ratio. It was concluded, therefore, that in both sporadic and endemic euthyroid goiters, factors other than goiter size and TSH, such as hypoiodination of Tg may be responsible for the elevated Tg secretion.

We carried out contemporaneous daytime blood sugar and growth hormone (HGH) determinations in eight juvenile and six middle-aged diabetics under both poor and good metabolic control. A continuous blood sampling technic was used. The following results were obtained: 1. HGH values in poorly controlled diabetics were higher and more fluctuating than in normals of a corresponding age. 2. After good control was reached, a significant HGH decrease was observed in all patients but one. In this condition HGH levels were normalized in middle-aged diabetics but not in juvenile ones. In the latter group HGH values, even if decreased, were persistently higher than in controls of the same age. 3. No difference was observed between newly diagnosed diabetics and patients known to have had diabetes for some years. Our data support the suggestion that HGH abnormalities in diabetes are a consequence of the metabolic disturbance.

Extracellular recordings were carried out in the visual cortex of behaving monkeys trained on a fixation/detection task, during which a target light was displayed stationary or suddenly moving on a tangent translucent screen. The responses of visual cortical cells to fast moving stimuli during steady fixation and those obtained during rapid eye movements (saccades) which moved their receptive field across a stationary stimulus, were studied. Areas V1 and V2 were explored. When tested with rapidly moving stimuli (500 deg/sec) during steady fixation, neurons in each area behaved in almost the same way. About one fourth of them were activated, the remainder showing either no response (little more than a half of them) or a reduction of the spontaneous firing rate. In both areas, some of the neurons activated during steady fixation did not respond or responded very weakly during eye motion at saccadic velocity (500 +/- 50 deg/sec). Neurons of this type, which we refer to as 'real motion' cells, could somehow contribute to the maintenance of visual stability during the execution of large eye movements.

We have characterized the GH clinical preparation available in Italy (Grorm, Serono) by gel chromatography and immunoreactivity. Only 50-60% of this preparation can be identified with the active GH monomeric form. Both higher and lower molecular weight compounds are present as well. Then, using a radioimmunoassay technique, we looked for anti-GH antibodies in 21 subjects under Grorm treatment and found them in 6 paitents (28.6%). Two subjects having anti-GH antibodies with high affinity had a lower growth rate. These data suggest that anti-GH antibodies measurement is clinically useful in patients treated with this GH preparation. A more purified preparation should be used when a slowing down of the growth rate is observed in the presence of anti-GH antibodies.

Direct projections from visual areas 17, 18, 19, and lateral suprasylvian visual area (LS) to the striatum were searched for in 12 adult cats using the autoradiographic technique to detect neuronal pathways. Striatal labels were found only after injections in areas 19 and LS. Projections homolateral to the injection sites were observed from both areas to the head and body of the caudate nucleus and to the putamen. Contralateral projections were found from both areas 19 and LS: however, area 19 did not project to the contralateral putamen. The extent of contralateral projections was smaller and they were confined within the same regions as the homolateral ones. Silver grains were often arranged in cluster-like patches, which were more evident ipsilaterally, in the head of the caudate nucleus and after injections in area LS. The present data support the view of a not strictly topographical segregation of striatal projections from the cat visual cortex.

Single unitresponses to photic stimuli of variable duration were studied in the cat visual areas 17 and 18. The closed-chamber technique was used to record extracellularly impulsive electrical activity in locally anaesthetized, Flaxedil-paralyzed and artificially ventilated cats. Stimulus duration ranges between 0.020 and 10 sec, the background luminance and the intensity of stimuli being constant. We found a first group of cells which fire independently of the stimulus duration; a second group which fire in close relation to the stimulus duration in a rather wide range of values, and a third group which fire monotonously as long as the stimulus goes on. The three groups of cells are supposed to be three functionally different types of cortical cells.

Extracellular recordings were carried out in the primary visual cortex of behaving monkeys. Neurons were activated by moving a visual stimulus on their receptive fields during periods of steady fixation and by moving their receptive fields (smooth pursuit eye movements) on a motionless visual stimulus. Regarding non-oriented cells, they turned out to be activated by the visual stimulation both during steady fixations and smooth pursuit eye movements. Therefore, the non-oriented cells we studied seem not to receive an extraretinal signal related to the slow eye movements.

In order to examine whether thyroid hormone concentration interfere with the thyroid gland responsivity to TSH, paired studies on the effect of short-term T3 treatment on T4 response to exogenous TSH ( 5 I.U. i.m.) were carried out in 10 euthyroid volunteers. During T3 administration ( 120 mcg/day for 4 days starting 48 hr before TSH injection) a significant decrease in T4 concentrations was observed both prior to and after TSH, with an inhibition of the T4 response ranging from 36-77% as calculated from the area under the response curve. The present data are in agreement with the existence of a "short-loop" thyroid-thyroid regulatory mechanism in man. In fact, the decreased percent rise of T4 after TSH suggests an inhibitory effect of T4 release following TSH, even though a modification of T4 kinetic parameters during T3 administration may account for a portion of the lowering of T4 blood concentrations.

Extracellular recordings were carried out in the primary visual cortex of behaving macaque monkeys. Neurons were activated by moving a visual stimulus across their receptive fields during periods of steady fixation and by moving their receptive fields (by visual tracking) across a motionless visual stimulus, taking care that the velocities of stimulus and eye movements were the same. The total cell population (108 neurons) ws divided into 3 groups according to the cell sensitivity to visual stimulus orientation (non-oriented cell and oriented cells) and to the presence or absence of antagonistic areas in in the receptive fields (oriented cells with antagonistic areas). All the non-oriented cells (n = 14) showed almost the same response to visual stimulation both during steady fixation and during visual tracking. Out of a total number of 86 oriented cells, 77 turned out to be activated by the visual stimulation both during fixation and tracking. Eight oriented cells gave a very weak response or no response at all to visual stimulation during smooth pursuit eye movements and one neuron of the same group showed a greater response during visual tracking than during fixation. Six out of 8 oriented cells with antagonistic areas showed almost the same response to the two types of visual stimulation, while the remaining two neurons showed very weak responses during smooth pursuit eye movements. Our results show that a small percentage (about 10%) of striate neurons in macaque monkeys gave very different responses to the same physical stimulation at retinal level, according to the presence or absence of slow eye movements (smooth pursuit eye movements). The activity of these neurons seems to be related to the real movement of something in the visual world, in spite of the retinal image movement per se.

The effect of short-term dexamethasone administration (8 mg daily for 3 days) on thyroid hormone response to exogenous TSH (bovine TSH, 5 IU i.m.) was studied in 16 euthyroid volunteers. Serum T3 and T4 concentrations were measured by radio-immunoassay prior to and 2, 6, 12, 24, and 49 hr after bTSH injection, both under basal conditions and during dexamethasone treatment. In all subjects bTSH administration raised both T3 and T4 concentrations significantly. Dexamethasone treatment induced a slight depression of endogenous TSH (m +/- SEM = 2.0 +/- 0.4 versus 1.6 +/- 0.3 muU/ml) and T4 (6.8 +/- 0.4 versus 6.1 +/- 0.2 mug/100 ml) basal values and a significant decrease in T3 value (1.16 +/- 0.09 versus 0.64 +/- 0.06 ng/ml, p = 0.005). The mean increment of both T3 and T4 after bTSH injection was percentually unchanged during dexamethasone treatment but, due to lowered basal value, T3 levels at each time interval after TSH + dexamethasone were significantly lower than the corresponding values observed after TSH alone. The present data show that high dexamethasone doses decrease T3 serum levels significantly without inhibiting T3 response to TSH stimulation. Only a slight lowering was observed in T4 levels.

The reproductive hormone function was investigated in three subjects, two brothers and one unrelated patient, with a Robertsonian translocation, who had come to us because of infertility. Basal levels of LH, FSH, testosterone, 17-beta-estradiol and prolactin were repeatedly measured by radioimmunoassays. In addition, clomiphene citrate, synthetic LH-RH, hCG and TRH tests were carried out. Karyotypes complemented by G-banding and C-banding, repeated semen analyses, and testicular biopsies were also obtained. The karyotype of all three subjects was 45, XY-13, -14, +t(13; 14) (p11; q11). Semen analyses showed oligozoospermia, and reduced or reduced/normal sperm motility. In addition, a high percentage of atypical forms was present in all three subjects. Reproductive hormone measurements in our three patients were substantially normal. Only one of the two brothers exhibited slightly low LH and testosterone levels. Both brothers also had elevated estradiol levels. Gonadotropin and testosterone responses to respective provocative stimuli, as well as prolactin elevation following TRH, were normal. In conclusion, the semen abnormalities observed in these three subjects with Robertsonian translocation appear to be responsible for their impaired fertility. However, the reason why some carriers of the same translocation are fertile and some others are subfertile or infertile remains unclear. It might be speculated that an individual genetic variability is responsible for different degrees of spermatogenic failure, accompanied, in more severe cases, also by reproductive hormone disorders.

This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 +/- 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins and urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis.

1. The projections from the superior temporal sulcus (STS) visual area to pontine nuclei were studied in the macaque monkey by the autoradiographic tracing method. Microinjections of a mixture of L-[5-3H] proline and L-[4,5-3H] leucine were carried out in the posterior band and the floor of the caudal half of the STS. Survival time was always 7 days. 2. The STS visual area projects to the dorsolateral part of ipsilateral pontine nuclei. Terminal projections are distributed in patches in the whole rostro-caudal extent of the pons. 3. These findings support the view that the STS visual area in the macaque monkey is homologous to the postero-medial lateral suprasylvian area in the cat.

Extracellular recordings were carried out in the primary visual cortex of behaving macaque monkeys. Neurons were activated by moving a visual stimulus across their receptive fields during steady fixation and by moving their receptive fields (by visual tracking) at the same velocity across a stationary visual stimulus. Out of a total number of 123 cells studied, 111 were activated by the visual stimulation both during fixation and tracking. The remaining 12 cells showed good response during fixation and very weakened response during tracking. Our results show that a small percentage of striate neurons in macaque monkey could discriminate between the real motion of an object in the visual world and the self-induced displacement of its retinal image.