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1.
Tissue Cell ; 51: 24-31, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29622084

ABSTRACT

We studied the effect of alcohol on the pineal gland of 48 male Wistar rats. Animals were divided into control and experimental groups. The experimental group underwent a previous progressive alcoholisation period with ethanol diluted in water at a concentration of 40%. Animals were sacrificed at 3, 6, 9 and 12 months, and the ultrastructure, karyometric indices, and number of synaptic bodies in the pineal gland were analysed. The results showed progressive morphologic alterations in the ethanol-treated animals, which culminated in fatty degeneration of the pineal parenchyma after 6 months. The karyometric indices decreased in both the central and peripheral areas compared with the control group. Moreover, the seasonal rhythmicity observed in the controls disappeared in the experimental groups, whose number of different populations of synaptic bodies (synaptic ribbons and synaptic spherules) considerably lowered with inversion of their normal seasonal rhythm. These results support that chronic alcoholisation leads to fatty degeneration of the pineal parenchyma, and a considerable alteration in nuclear functional rhythms and synaptic bodies.


Subject(s)
Central Nervous System Depressants/toxicity , Ethanol/toxicity , Pineal Gland/drug effects , Pineal Gland/pathology , Animals , Circadian Rhythm/drug effects , Male , Microscopy, Electron, Transmission , Pineal Gland/ultrastructure , Rats , Rats, Wistar
2.
Eur J Neurosci ; 23(10): 2731-8, 2006 May.
Article in English | MEDLINE | ID: mdl-16817876

ABSTRACT

The hippocampal theta rhythm is generated by the pacemaker activity of the medial septum-diagonal band of Broca (MS/DBB) neurons. These nuclei are influenced by brainstem structures that modulate the theta rhythm. The aim of the present work is to determine whether the nucleus incertus (NI), which has important anatomical connections with the MS/DBB, contributes to the hippocampal theta rhythm generation in rats. Hippocampal field activity was recorded in urethane-anaesthetized rats. Electrical stimulation of the NI not only evoked theta rhythm in the hippocampus, but also decreased the amplitude of delta waves. Unit recordings in the NI revealed either a non-rhythm discharge pattern in most neurons (76%), or a rhythm activity at 13-25 Hz in the remaining neurons. The firing rate of these neurons increased during the presence of theta rhythm evoked by either sensory or reticularis pontis oralis nucleus (RPO) stimulation. Electrolytic lesions of NI, or the microinjection of the gamma-aminobutyric acid (GABA)A agonist muscimol, abolished the theta rhythm evoked by RPO stimulation. Consequently, the NI may be a relay station between brainstem structures and the MS/DBB in the control of the hippocampal theta rhythm generation.


Subject(s)
Brain Mapping , Hippocampus/anatomy & histology , Hippocampus/physiology , Mesencephalon/anatomy & histology , Neural Pathways/anatomy & histology , Theta Rhythm , Animals , Diagonal Band of Broca/anatomy & histology , Diagonal Band of Broca/physiology , Electric Stimulation , Female , Male , Mesencephalon/physiology , Microelectrodes , Neural Pathways/physiology , Rats , Rats, Wistar , Septum of Brain/anatomy & histology , Septum of Brain/physiology
3.
Histol Histopathol ; 17(1): 205-12, 2002 01.
Article in English | MEDLINE | ID: mdl-11813871

ABSTRACT

Morphological and physiological studies suggest a possible division of the pineal parenchyma into an external or "cortical" and another central or "medullar" layer. We have studied the possible influence of the light/dark, seasonal and lunar cycles on the nuclear size of the pinealocytes of the rat in both the hypothetical "cortical" and "medullar" layers. Forty male Wistar rats were used. Experiment was carried out in two seasons, winter and spring, two lunar phases, full moon and new moon, and the two circadian phases, photophase and scotophase. The nuclear volume of the pinealocytes, calculated from the Jacobj's formula, was the karyometric parameter used as measurement of the nuclear size. Main results showed that nuclear volume of the cortical pinealocytes was greater than that of the medullar pinealocytes only during the photophases of winter new-moon days and spring full moon days, whereas in all the remaining situations, the greater nuclear sizes were found in the pinealocytes of the medullar layer. These results support the existence of independent morphological variations of the pinealocyte in the central and peripheral zones of the pineal gland.


Subject(s)
Cell Nucleus/ultrastructure , Moon , Pineal Gland/physiology , Pineal Gland/ultrastructure , Seasons , Animals , Darkness , Light , Male , Photoperiod , Pineal Gland/anatomy & histology , Rats , Rats, Wistar , Tissue Fixation
4.
Histol Histopathol ; 17(1): 213-22, 2002 01.
Article in English | MEDLINE | ID: mdl-11813873

ABSTRACT

Synaptic bodies (SB) are ultrastructural organelles observed in the pinealocytes of mammals. According to its shape, they have been classified into synaptic ribbons (SR), synaptic spherules (SS), and intermediate synaptic bodies (ISB). They have been related to the melatonin regulation and production mechanisms of the pineal gland. Circadian and circannual fluctuations of both melatonin and SB have been reported. The possibility that other external factors, apart from light-dark or seasonal cycles, might influence pineal function has been suggested. We studied the evolution of the number of SB and serum melatonin levels not only during light-dark and seasonal phases but also during lunar cycles. Forty male wistar rats were used. Experiment was first carried out in winter and repeated identically in spring. Each season, one group of animals was killed during the new-moon days and a second group during the full-moon days: half of both groups in the photophase and the other half in the scotophase. The number of SB was measured at electron microscopic level whereas serum melatonin levels were determined by radioimmunoassay techniques. Main results showed that SR number and serum melatonin levels were higher during scotophases, winter and full-moon days. The SS only showed a light predominance during winter, whereas predominance of the ISB was found only during the scotophases. These results support the influence of the photophasic factors on the SR and ISB variations. In the case of the SS the influence of the lunar cycles is always dependent on the other factors. Finally, the serum level of melatonin is clearly influenced by the photophasic rhythms and the seasonal periods but not by the lunar cycles.


Subject(s)
Melatonin/blood , Moon , Pineal Gland/innervation , Pineal Gland/physiology , Seasons , Synapses/physiology , Animals , Darkness , Light , Male , Microscopy, Electron , Pineal Gland/ultrastructure , Radioimmunoassay , Rats , Rats, Wistar , Synapses/ultrastructure , Tissue Fixation
5.
Eur. j. anat ; 5(2): 77-81, sept. 2001. tab
Article in En | IBECS | ID: ibc-15545

ABSTRACT

Refractive surgery by means of excimer laser results in thinner postoperative corneas following corneal photoablation. This implies the need to previously measure the central corneal thickness in order to avoid the risk of keratectasia. In recent years and after the introduction of excimer laser refractive surgery, several studies have focused on corneal morphometry in myopic eyes. However, we have not found any references to hyperopic eyes. Following on from this, we have studied central corneal thickness in 100 healthy hyperopic eyes by using ultrasonic pachymetry. Patients were subdivided by refractive errors into group 1 (manifesting spherical equivalent refraction ? +4.00 diopters) and group 2 (manifesting spherical equivalent refraction > +4.00 diopters). In group 1, central corneal thickness was 555.20±33.31 ?m (mean ± standard deviation) and in group 2 it was 548.95±31.87. No significant differences were found between group 1 and group 2 (p= 0.346). In group 1 there were significant differences in mean central corneal thickness between females and males (p= 0.012) but not in group 2 (p= 0.947). No significant differences in the mean values of central corneal thickness as a function of age for the members of group 1 and group 2 were noted (p= 0.198 and p= 0.628, respectively). Central corneal anatomy in healthy hyperopic eyes is similar to that seen in myopic eyes (AU)


La cirugía refractiva con láser excimer da como resultado córneas postoperatorias adelgazadas tras la fotoablación corneal. Esto implica la necesidad de medir previamente el espesor corneal central para evitar el riesgo de queratectasias. En años recientes y tras la introducción de la cirugía refractiva con láser excimer, diversos estudios se han centrado en la morfometría corneal de los ojos miopes.Sin embargo, no hemos encontrado referencias a los ojos hipermétropes. Debido a esto, hemos estudiado el espesor corneal central en 100 ojos hipermétropes sanos empleando la paquimetría ultrasónica. Los pacientes fueron subdivididos según el error refractivo dentro del grupo 1 (equivalente esférico refractivo manifiesto ? + 4.00 dioptrías) y grupo 2 (equivalente esférico refractivo manifiesto > + 4.00 dioptrías).En el grupo 1, el espesor corneal central fue de 555.20?33.31 µm (media ? desviación estándar) y en el grupo 2 fue 548.95?31.87. No se encontraron diferencias significativas entre el grupo 1 y el grupo 2 (p=0.346). En el grupo 1 se encontraron diferencias significativas en el espesor corneal central entre las mujeres y los varones (p=0.012) pero no en el grupo 2 (p=0.947).No se encontraron diferencias significativas en los valores medios del espesor corneal central en función de la edad para los miembros del grupo 1 y del grupo 2 (p=0.198 y p=0.628, respectivamente).La anatomía corneal central en los ojos hipermétropes sanos es similar a la observada en los ojos miopes (AU)


Subject(s)
Adolescent , Adult , Female , Male , Humans , Photorefractive Keratectomy , Cornea , Hyperopia/surgery , Hyperopia , Statistics, Nonparametric
6.
J Chem Neuroanat ; 21(4): 295-312, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11429271

ABSTRACT

The chemoarchitecture of the periaqueductal gray has been extensively studied, based on acetylcholinesterase reaction and comparing it to other chemical markers. We have divided the periaqueductal gray into four main longitudinal columns, namely dorsomedial, dorsolateral, lateral and ventrolateral. We also identified the dorsal midline column, the supraoculomotor cap and the juxta-aqueductal ring. The acetylcholinesterase gave rise to a strong reaction in the outer half of the lateral column, the outer half of the dorsomedial column, the supraoculomotor cap and the ventral half of the juxta-aqueductal ring. This labeling was in part complementary to that of the NADPH diaphorase and allowed the lateral column to be differentiated from the ventrolateral column. However, the inner half of both lateral and ventrolateral columns displayed the same chemical properties including acetylcholinesterase, tyrosine hydroxilase and serotonin. Thus, from the chemical view, these inner halves should be considered as one different region. Finally, the juxta-aqueductal ring was composed of two clearly different halves, i.e. dorsal and ventral. The dorsal half did not show any clear differences from the above columns and was negative for acetylcholinesterase, NADPH diaphorase and tyrosine hydroxilase, while the ventral half was clearly different from the lateral and ventrolateral columns and displayed a positive reaction to all those chemical markers. From these results, we strongly suggest the use of acetylcholinesterase histochemistry as a tool for accurate parcellation of the periaqueductal gray.


Subject(s)
Acetylcholinesterase/metabolism , Periaqueductal Gray/anatomy & histology , Periaqueductal Gray/enzymology , Animals , Glutamic Acid/metabolism , Histocytochemistry , Image Processing, Computer-Assisted , Male , NADPH Dehydrogenase/metabolism , Rats , Rats, Sprague-Dawley , Tyrosine 3-Monooxygenase/metabolism
7.
Eur. j. anat ; 4(3): 169-176, dic. 2000. ilus
Article in En | IBECS | ID: ibc-15532

ABSTRACT

Eighteen cross-bred male cats (2650±750 g) were kept for three weeks with environmental lighting and under the same feeding (ad libitum) and temperature conditions (18-22°C). The animals were sacrificed in the spring in groups of three at 4 h intervals with the following GMT time sequence: 06:00, 10:00, 14:00, 18:00, 22:00, and 02:00 hours. During the circadian cycle, significant variations were observed in the number of synaptic ribbons and synaptic spherules in the pineal glands of the animals, with maximum and minimum values at 02:00 and 14:00 hours, and at 10:00 and 02:00 hours, respectively. Analysis of variance (ANOVA) showed these differences to be statistically significant (F-ratio: 43.513; p<0.0001 for synaptic ribbons, and F-ratio: 6.0; p<0.005 for synaptic spherules). The number of synaptic ribbons was found to be significantly higher (p<0.0001) at night (67.3%) than in the daytime (32.6%), while the number of synaptic spherules was 59.1% and 40.8% in the daytime and at night, respectively. The polynomial correlation between the evolution of the synaptic ribbons and the time point was very positive (R = 0.8). The circadian variations observed in the intermediate synaptic bodys (ISBS) population were not significant, either for triangular synaptic bodies (TSB) (p<0.07) or for rectangular synaptic bodies (RSB) (p<02). Finally, the total number of synaptic ribbons observed in the photophase merged to form "fields" of three or more elements. These fields were more commonly observed in pinealocyte prolongations than in areas close to the nucleus (AU)


Se mantuvieron dieciocho gatos machos de cepa cruzada (2650ñ750 g) durante tres semanas con luz ambiental y bajo las mismas condiciones de alimentación (ad libitum) y temperatura (18-22º C). Los animales fueron sacrificados en primavera en grupos de tres a intervalos de 4 horas en las siguientes secuencias horarias: 06:00, 10:00, 14:00, 18:00, 22:00 y 02:00 horas. Durante el ciclo circadiano se observaron variaciones significativas en el número de botones sinápticos y esférulas sinápticas en las glándulas pineales de los animales, con valores máximos y mínimos a las 02:00 y 14:00 horas, y a las 10:00 y 02:00 horas, respectivamente. El análisis de la varianza (ANOVA) demostró que estas diferencias fueron estadísticamente significativas (F-ratio: 43.513; p<0.0001 para los botones sinápticos y F-ratio: 6.0; p<0.005 para las esférulas sinápticas). El número de botones sinápticos fue significativamente mayor (p<0.0001) por la noche (67.3 por ciento) que durante el día (32.6 por ciento), mientras que el número de esférulas sinápticas fue del 59.1 por ciento y 40.8 por ciento durante el día y durante la noche, respectivamente. La correlación polinómica entre la evolución de los botones sinápticos y el punto horario fue muy positiva (R = 0.8). Las variaciones circadianas observadas en la población de cuerpos sinápticos intermedios (ISBS) no fueron significativas, bien para los cuerpos sinápticos triangulares (TSB) (p<0.07) o bien para los cuerpos sinápticos rectangulares (RSB) (p<0.2). Finalmente, el número total de botones sinápticos observados en la fase de luz se combinaron para formar "campos" de tres o más elementos. Estos campos se observaron generalmente más en las prolongaciones de los pinealocitos que en las áreas próximas al núcleo (AU)


Subject(s)
Animals , Cats , Male , Synaptic Membranes , Pineal Gland/cytology , Seasons , Analysis of Variance , Circadian Rhythm
8.
Neuroreport ; 7(15-17): 2749-52, 1996 Nov 04.
Article in English | MEDLINE | ID: mdl-8981460

ABSTRACT

The distribution of c-fos proto-oncogene expression has been studied in the periaqueductal grey matter (PAG) of non-intentional-stimulated rats by immunohistochemistry. A mean number of 53 +/- 9 Fos-like immunoreactive cells per hemiPAG, distributed into three groups, dorsolateral, lateral and ventrolateral, was found. The dorsolateral and the lateral groups appeared along the entire rostrocaudal PAG, whereas the ventrolateral group appeared only in the caudal half. These results reveal new data on the number and extent of the longitudinal columns within the hypothetical organization of the PAG. They also indicate a continuous activation of a significant population of neurones in the PAG, in agreement with the suggested role of the PAG in the modulation of internal information.


Subject(s)
Periaqueductal Gray/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Animals , Female , Immunohistochemistry , Male , Rats , Rats, Wistar
9.
Arch Ital Biol ; 134(3): 235-48, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8805954

ABSTRACT

Sixty-four male Wistar rats (mean weight 215 +/- g) were divided into two groups of 32 animals each, with four additional subgroups (n = 8). The experimental group was subjected to immobilization stress for 24 hours and sacrificed during the photo - (10:00-14:00 hours) and scotophases (00:00-02:00 hours) of spring and winter. Photophase and seasonal differences were observed (p < 0.0001) between the corticomedullary karyometric values obtained in the control group. Similar results were obtained in the experimental group, though the seasonal differences were greater and favored spring (p < 0.0001), while the photophase differences were less important (p < 0.03). The number of synaptic ribbons showed a significant inversion of the physiological day/night ratio in both seasons. Similar results were obtained for the melatonin serum levels. The results suggest that photophase and season may be conditioning factors in the albino rat regarding pineal response to stress immobilization.


Subject(s)
Melatonin/blood , Pineal Gland/anatomy & histology , Pineal Gland/physiology , Seasons , Stress, Psychological/metabolism , Stress, Psychological/pathology , Animals , Cell Nucleus/physiology , Cell Nucleus/ultrastructure , Immobilization , Karyometry , Male , Periodicity , Pineal Gland/ultrastructure , Rats , Rats, Wistar , Synapses/physiology , Synapses/ultrastructure
10.
Histol Histopathol ; 7(4): 679-87, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1457990

ABSTRACT

Circadian and seasonal variations were observed in the karyometric index of pinealocytes in the cortical and medullary regions of the distal pineal body. The study involved 70 Wistar rats over a 24-hour interval (0:6, 10:00, 14:00, 18:00, 22:00, 02:00, 06:00 h) during two natural photoluminous periods, i.e. late summer (Long photoperiod) and Winter (Short photoperiod). The results show a difference between the high and low points of both photoperiods. Cortico-medullary differences are found at different times of day during long photoperiod (0:6; 10:00; 14:00 and 18:00 h.) and short photoperiod (14:00; 22:00 and 02:00 h.). The variance analyses between nuclear volume and point-time and between nuclear volume, point-time and location are significative. A high correlation between circadian rhythms and volumetric variations in both layers and photoperiod are found. The results also show significant differences in cortico-medullary karyometric indices between both seasons as well as between the diurnal and nocturnal hours of both photoperiods. It is suggested that the pineal body of the rat is influenced by circadian and seasonal photoperiod and may have groups of cells with different functional characteristics, depending on their location within the gland.


Subject(s)
Cell Nucleus/ultrastructure , Cerebral Cortex/ultrastructure , Circadian Rhythm/physiology , Medulla Oblongata/ultrastructure , Pineal Gland/ultrastructure , Seasons , Animals , Histocytochemistry , Male , Rats , Rats, Wistar
11.
Acta Anat (Basel) ; 143(4): 289-93, 1992.
Article in English | MEDLINE | ID: mdl-1323903

ABSTRACT

In continuation of earlier studies, we have investigated the influence of 52-Gs (50-Hz) magnetic fields on the evolution of pinealocyte 'synaptic ribbons' and serum melatonin levels in rats, following 30 min daily exposure. The animals were sacrificed after 1, 3, 7, 15 and 21 days. A significant decrease in the number of synaptic ribbons was observed after 15 and 21 days, together with a significant drop in serum melatonin concentrations after 15 days. The mediating role of the retina in these modifications and magnetic field effects is discussed.


Subject(s)
Electromagnetic Fields , Inclusion Bodies/ultrastructure , Melatonin/blood , Pineal Gland/ultrastructure , Animals , Male , Melatonin/metabolism , Pineal Gland/metabolism , Rats , Rats, Inbred Strains
12.
Acta Anat (Basel) ; 145(4): 430-3, 1992.
Article in English | MEDLINE | ID: mdl-10457789

ABSTRACT

We have studied the ultrastructure of the pinealocyte after 24 h of immobilization. Thirty male albino rats (230 +/- 10 g) were used; the animals were divided into two groups of 15 each. One group was immobilized for 24 h (10.00 h a.m. to 10.00 h a.m.), whereas the other group was used as control. All animals were sacrificed between 10.00 and 14.00 h of the following day. Ultrastructural observations showed an euchromatinic nucleus with numerous giant 'lipid droplets' as well as abundant long 'synaptic ribbons' that were significantly more abundant than in the controls (p < 0.0005). These findings all suggest an increase in pineal activity following 24-hour immobilization.


Subject(s)
Immobilization/adverse effects , Organelles/ultrastructure , Pineal Gland/ultrastructure , Animals , Cytoplasmic Granules/ultrastructure , Male , Microscopy, Electron , Pineal Gland/physiopathology , Rats , Stress, Physiological/pathology , Stress, Physiological/physiopathology , Time Factors
13.
Histol Histopathol ; 6(3): 387-93, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1810537

ABSTRACT

Seventy Wistar rats are used to study the changes in pineal intercellular canaliculi over a 21-hour period and for two different photoperiods (pre-autumn, first week of September, and winter, first week of February). The study considers these changes at pineal body, cortical and medullar level separately, and compares the values obtained. The results show variations in canalicular surface at different point times (10:00, 14:00, 18:00) and for both photoperiods. The variations are found to favour the cortical layer, and are also observed between nocturnal and diurnal hours. Canalicular surface to greater during the diurnal hours of both photoperiods. Interesting histological findings are described that suggest an important function of the intercellular canaliculi in pineal gland metabolic exchange.


Subject(s)
Circadian Rhythm , Pineal Gland/ultrastructure , Animals , Environment, Controlled , Extracellular Space , Light , Male , Neuroglia/ultrastructure , Rats , Seasons , Synapses/ultrastructure , Time Factors
14.
J Hirnforsch ; 32(6): 779-86, 1991.
Article in English | MEDLINE | ID: mdl-1821424

ABSTRACT

A study is made of the pinealocyte karyometric index and pineal gland ultrastructure in 60 male Wistar rats (250 g on average) sacrificed 1, 3, 7, 15 and 21 days after commencing application of a magnetic field (intensity, 52 Gauss; frequency, 50 Hz) for a period of 30 minutes daily. A progressive decrease was observed in karyometric index corresponding to both the peripheral and central gland region, with a significant difference between the two after 3 and 7 days (p less than 0.0001). A significant increase in lipid activity was also seen during the same period. Pineal gland structural organization during the experimental period is evaluated at both light and electron microscope level.


Subject(s)
Electromagnetic Fields/adverse effects , Pineal Gland/anatomy & histology , Animals , Histocytochemistry , Male , Microscopy, Electron , Pineal Gland/cytology , Pineal Gland/radiation effects , Rats , Rats, Inbred Strains , Time Factors
16.
Acta Anat (Basel) ; 130(3): 228-31, 1987.
Article in English | MEDLINE | ID: mdl-3434174

ABSTRACT

A study is made of the number of pineal gland synaptic ribbons in 35 male Wistar rats over a 24-hour period during the months of September and February, in correlation to the serum melatonin levels during the same periods and photophases. The results of the study confirm those reported by others authors and suggest that the synaptic ribbons may be the stimuli-transmitting organs facilitating pineal secretory function.


Subject(s)
Circadian Rhythm , Light , Melatonin/blood , Periodicity , Pineal Gland/ultrastructure , Synapses/ultrastructure , Animals , Male , Rats , Rats, Inbred Strains
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