Biomedical subjects

C Iñiguez

Publications and source records attributed to C Iñiguez.

12 recordsLinked to original sources

PubMed1992

Axon types classified by morphometric and multivariate analysis in the rat optic nerve.

Calibers of the rat optic nerve axons distribute unimodally and it is difficult to distinguish groups among them. However, these fibers arose from 3 types of ganglion cells and showed 3 conduction velocities. Performing a cluster analysis over several ultrastructural parameters we found 3 main groups of fibers. These groups are present in a very similar proportion to the ganglion cells groups described in the rat retina.

Animals↗

PubMed1992

Developmental stages of the vomeronasal organ in the rat: a light and electron microscopic study.

This paper describes the development of the rat vomeronasal organ from the stage of anlage until adulthood. Groups of four rats were sacrificed daily from prenatal day 13 (E13) until birth; at days 2, 4, 7, 10, 14 and 16 after birth; weekly from day P21 to P42 plus an additional group of adults. The vomeronasal organs were processed for light microscopy, including alcian blue-PAS and NADH-diaphorase reactions, and also for electron microscopy. For summarizing our results we propose the following developmental stages: 1. Anlage (E13). 2. Early morphogenesis (E14-16). 3. Late morphogenesis (E17 to birth). 4. Initiation of secretory activity (First postnatal week). 5. Cytoarchitectural maturity (2nd postnatal week). 6. Complete maturity (From 3rd postnatal week onwards). Our results on the maturation of the histological structure and the histochemical reactions, indicate that there may be some functional activity at birth but the development of the organ still continues during the first three postnatal weeks to acquire its full functional capability.

Animals↗

PubMed1991

Nematosomes in external horizontal cells of white perch (Roccus americana) retina: changes during dark and light adaptation.

Cytoplasmic inclusions resembling nucleoli and termed nematosomes have been described in several areas of the nervous system but not in the retina. Here we report the presence of these structures in the external horizontal cells of white perch (Roccus americana). Nematosomes were larger and more numerous in dark-adapted retinas than in light-adapted ones. An inverse relation of horizontal cell spinules was found in these cells, suggesting that electron-dense material observed in spinules may originate from nematosomes.

Adaptation, Ocular↗

PubMed1991

Antiphospholipid antibodies in migraine.

We studied the presence of serum antiphospholipid antibodies (APA) in 35 patients with migraine and 75 controls. None of the controls showed APA, while we found these antibodies in five patients out of the 35 studied (p = 0.003). The clinical features of migraineurs with APA were similar to those of patients without them. After a follow-up of one to two years, no patient suffered any neurological complications or developed any clinical features that would suggest the presence of autoimmune disease. Our results suggest that APA are not prominent in the pathogenesis of migraine attacks, or significant in the course of otherwise healthy migraine patients.

Adult↗

PubMed1990

Postnatal development of striatal connections in the rat: a transport study with wheat germ agglutinin-horseradish peroxidase.

This paper deals with the postnatal development of afferent and efferent connections of the rat striatum as revealed by the transport of horseradish peroxidase conjugated with wheat germ agglutinin (WGA-HRP). Tracer was injected weekly from birth to the end of the first postnatal month in the head of the caudate nucleus. To control for transport from cortical areas contaminated by the micropipette, injections in newborn rats were made by either vertical or lateral penetrations. In addition some newborn and 14-day-old animals were injected only in the cortex. The results showed that at birth there was retrograde transport to the thalamus, substantia nigra and raphe nuclei. Labelling in the cortex was seen at birth but was probably due to cortical contamination. Transport from the striatum was clearly established on day 7, when a few labelled neurons were observed on both the ipsi and contralateral sides. These neurons increased in number and were distributed through layers III to VI by day 14. At this time labelled cell bodies were observed in the claustrum and lateral amygdaloid nucleus as well as in the globus pallidus and entopeduncular nucleus. On day 21 the contralateral labelling of the lateral amygdaloid nucleus was apparent. The anterograde transport from the striatum to globus pallidus, entopeduncular nucleus and substantia nigra was already visible at birth although its intensity increased during the first postnatal month.

Aging↗

PubMed1990

Alterations in prolactin secretion during the 1st postnatal month following perinatal dopaminergic blockade with haloperidol.

This research was intended to study the effects of perinatal haloperidol administration on the postnatal secretion of prolactin (PRL) with the aim of investigating the existence of a 'critical period' during which the lack of dopamine influence could cause long-term alterations in the secretion of this hormone. A first group of animals, composed of pregnant rats, was injected daily with haloperidol (1 mg/kg) from day 16 of gestation to delivery. A second group of newborn rats received the same dose from days 2 to 6 after birth. Pituitary and serum PRL were measured weekly by radioimmunoassay during the 1st postnatal month in pups from the injected mothers, in postnatally injected rats, and in controls. The results showed a significant increase in the pituitary amounts of PRL that was more intense after the prenatal treatment, especially in the females. In serum, the prenatal treatment induced PRL levels higher than in the controls, whereas the postnatally injected group exhibited a V-shaped response which has been described as characteristic of neuroleptic withdrawal. These data confirm the existence of a 'critical period' during which perinatal administration of haloperidol alters the postnatal PRL production and secretion patterns. The persistence of high PRL contents in pituitary may reflect an alteration in the hormone synthesis and/or an increase in the rate of somatomammotrophes that differentiate into lactotrophes after suppression of dopamine influence. The high PRL levels in serum indicate a failure in the control of PRL release, perhaps after damaging the tuberoinfundibular neurons as a consequence of the high prolactinemia induced by the treatment.

Animals↗

PubMed1987

Morphological effects of chronic haloperidol administration on the postnatal development of the striatum.

The aim of this paper is to describe the morphological changes induced in the striatum after the administration of haloperidol during the first postnatal month, a period in which a lack of tolerance to treatment with neuroleptics has been reported. At the end of the treatment several morphological parameters were evaluated including neuron size and density and the synaptic profile areas of cross-sectioned dendrites and axon terminals. The results evidenced a loss of the smallest dendritic profiles without the rest of the parameters examined being affected. This response differs from the one observed in the adult rat striatum that does develop tolerance to haloperidol. It seems to more closely correspond to the changes found in the prefrontal cortex, a region that does not develop tolerance after chronic treatment with neuroleptics.

Animals↗

PubMed1985

Carbonic anhydrase in the carotid body and the carotid sinus nerve.

It is well known that carbonic anhydrase plays an important role in the physiological responses of carotid-body chemoreceptors to hypercapnia. Nevertheless the precise location of the enzyme within the carotid body has been a matter of controversy for many years. Using the Hansson method we found histochemical evidence that this enzyme is localized in type I cells. Type II cells and nerve terminals did not show enzymatic activity. These results allow us to define the carotid body as a secondary receptor in the context of the "acidic hypothesis" of transduction in the carotid body.

Animals↗

PubMed1985

A versatile and simple method for staining nervous tissue using Giemsa dye.

A method for staining nervous tissue with Giemsa dye is described. The procedure is easy to perform and works well on paraffin, celloidin and frozen sections. The results combine the properties of the Nissl stains with the polychromatism of the Romanowsky dyes. The method also provides good results for counterstaining autoradiographies, or when applied after horseradish or peroxidase-antiperoxidase techniques. In the latter case, Giemsa dye darkens the immunoreactive product in the same manner as osmium tetroxide but avoids the well-known risks of handling this toxic agent.

Animals↗

PubMed1984

Haloperidol pretreatment does not alter the Golgi staining of the striatum.

Two series of Wistar rats were treated with Haloperidol and the striata were stained with two different modifications of the Golgi method. The experimental animals of the first series received a single dose of Haloperidol i.p. and were sacrificed half an hour after the injection. The experimental rats of the second series were treated chronically with Haloperidol, beginning with 5 mg/kg and increasing this dose daily 0.2 mg/kg to reach a final dose of 10 mg/kg after four weeks of treatment. There were no differences in the staining of both series of animals when compared with their controls, whatever modification of the Golgi method was employed. As these results contradict those of Danner and Pfister (1982) the possible reasons of such a discrepancy are discussed.

Animals↗

PubMed1978

Effects of zinc deficiency on the chick embryo blastoderm.

A technique which permits the in vitro study of zinc deficiency in early embryos of Gallus domesticus is described using dithizone as a chelating agent. Zinc deficiency produces specific and constant lesions which are more severe as the embryo is cultivated in more early stages. The most serious alterations affect growth in general and the differentiation of the nervous system and mesoderm.

Animals↗

PubMed1978

Number, diameter and distribution of the rat optic nerve fibers.

Light- and electron-microscopic methods for nerve fiber counting and diameter measuring are described. These methods were applied to the rat optic nerve. Differences between light- and electron-microscopic results are shown. Coincidences and divergences with the current literature data are discussed.

Animals↗