Chronic treatment of haloperidol induces pathological changes in striatal neurons of guinea pigs: a light and electron microscopical study.

In the present work, we investigated whether there would be any change in histological structure of striatal neurons after haloperidol applications at different doses. Adult male guinea pigs were treated once-daily with saline (group 4, control) or haloperidol during 6 weeks, and the dose was 1, 2, or 3 mg/kg (groups 1, 2, and 3, respectively). After treatment, all animals were anesthetized and striata were dissected and examined. When striata were evaluated histologically, dark neurons and some degenerating striatal neurons had distinctive morphological changes consistent with cell death, including reduced neuronal size with nuclear and cytoplasmic shrinkage. Also, in sections of striata in groups 1 and 2, but not in group 3, more glial cells were observed than in those of the control group. In all treated groups, fibrous content of intersititium was paralelly increased by increasing dose. Ultrastructural investigation of striatal neurons in haloperidol-treated rats showed notched nuclei and many lysosomes. Moreover, degeneration of myelin, scarce microglial macrophages, expansion of nuclear intermembranous space, degenerated mitochondria, and vacuoles were found. Also, cytoplasmic swelling, lysosomes, and apoptotic bodies were present. These results suggest that haloperidol treatment may lead to damage in neurons via the necrotic process in both low- and high-dose applications.

Destructive Effects of Acidic Blood on the Intestines: Experimental Study.

OBJECTIVE: This study aimed to investigate the destructive effects of acidic blood on the intestinal structures, which has been reported as the most hazardous biochemical result of vagosympathetic autonomic imbalances in intensive care unit patients with subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: In total, 27 hybrid rabbits were used; 5 rabbits were used as a control group, 7 as the SHAM group into whom 1 cc saline was injected into the cisterna magna, and the remaining 15 were used as the study group. These animals received 1 cc of autologous arterial blood injection into the cisterna magna to create the SAH group. Blood pH values were recorded before, during, and after the experimental procedures. Computed tomography was performed to examine the intestinal morphology. Normal and degenerated epithelial cell densities of the intestine were estimated by stereological methods. The relationship between pH values and intestinal tissue changes was analyzed statistically using the Mann-Whitney U test. RESULTS: The mean blood pH values were 7.364±0.042 in the control group, 7.326±0.059 in the SHAM group, and 7.23±0.021 in the study group. Intestinal epithelial cell injury, desquamation of villus, and cell loss were observed. It is observed that the number of degenerated epithelial cells, fragmented villi numbers, and vacuoles significantly increased in the study group (p<0.05). CONCLUSION: Acidotic intestinal injury secondary to blood pH changes following SAH may be considered as a generalized and dangerous complication with their multiorgan insuficiency effect.

Thoracic sympathetic nuclei ischemia: Effects on lower heart rates following experimentally induced spinal subarachnoid hemorrhage.

BACKGROUND: The neuropathological mechanism of heart rhythm disorders, following spinal cord pathologies, to our knowledge, has not yet been adequately investigated. In this study, the effect of the ischemic neurodegeneration of the thoracic sympathetic nuclei (TSN) on the heart rate (HR) was examined following a spinal subarachnoid hemorrhage (SSAH). METHODS: This study was conducted on 22 rabbits. Five rabbits were used as a control group, five as SHAM, and twelve as a study group. The animals' HRs were recorded via monitoring devices on the first day, and those results were accepted as baseline values. The HRs were remeasured after injecting 0.5 cc of isotonic saline for SHAM and 0.5 cc of autolog arterial blood into the thoracic spinal subarachnoid space at T4-T5 for the study group. After a three-week follow-up with continuous monitoring of their HRs, the rabbit's thoracic spinal cords and stellate ganglia were extracted. The specimens were evaluated by histopathological methods. The densities of degenerated neurons in the TSN and stellate ganglia were compared with the HRs. RESULTS: The mean HRs and mean degenerated neuron density of the TSN and stellate ganglia in control group were 251±18/min, 5±2/mm3, and 3±1/mm3, respectively. The mean HRs and the mean degenerated neuron density of the TSN and stellate ganglia were detected as 242±13/min, 6±2/mm3, and 4±2/mm3 in SHAM (P>0.05 vs. control); 176±19/min, 94±12/mm3, and 28±6/mm3 in the study group (P<0.0001 vs. control and P<0.005 vs. SHAM), respectively. CONCLUSIONS: SAH induced TSN neurodegeneration may have been responsible for low HRs following SSAH. To date this has not been mentioned in the literature.

A New Determinant of Poor Outcome After Spontaneous Subarachnoid Hemorrhage: Blood pH and the Disruption of Glossopharyngeal Nerve-Carotid Body Network: First Experimental Study.

OBJECTIVE: The chemoreceptor network, consisting of the glossopharyngeal nerve and carotid body (GPN-CB), is essential for the regulation of blood pH. Its ischemic insults after subarachnoid hemorrhage (SAH), which may contribute to acidosis, have not been investigated. METHODS: Twenty-three hybrid rabbits were used. They were divided into 3 groups: 5 as a control group, 5 as a sham group, and the remaining 13 as the study group. Injections included 1 cm3 serum saline and 1 cm3 autolog arterial blood into the cisterna magna in the sham and study group, respectively. Blood pH values of all animals were recorded. After 2 weeks, animals were euthanized. The number of normal and degenerated neurons of the carotid bodies (CBs) was counted by stereologic methods and analyzed statistically. RESULTS: Two of 13 rabbits died within the second week. The mean blood pH values were measured as 7.35 ± 0.07 in the control group (n = 5), 7.33 ± 0.06 in the sham group (n = 5), 7.29 ± 0.05 in rabbits with slight acidosis (n = 6), and 7.23 ± 0.02 in rabbits with prominent acidosis (n = 7). In the control group, the average normal neuronal density of the CBs was 6432 ± 790/mm3 and the degenerated neuron density was 11 ± 3/mm3, whereas the degenerated neuronal density in CBs was 35 ± 8/mm3 in the sham group and 1034 ± 112/mm3 in the slight acidosis-developed group (n = 6; P < 0.05). Conversely, degenerated neuron density of CBs was 2134 ± 251/mm3 in the prominent acidosis-developed animals (n = 7; P < 0.005). Interestingly, in the rabbits who died, the degenerated neuron density of the CB was 3160 ± 840/mm3. CONCLUSION: An inverse relationship between neurodegeneration in the CB and pH values secondary to the disruption of the GPN-CB network after SAH was found, which may contribute to developing acidosis.

Number of axons in the right and left optic nerves of right-pawed and left-pawed rats: a stereologic study.

OBJECTIVE: To compare the number of axons in the right and left optic nerves of right- and left-pawed rats. STUDY DESIGN: In this study, optic nerve samples were obtained from right- and left-pawed rats and axon numbers of optic nerves and vice versa were stereologically and histologically evaluated. RESULTS: In the right-pawed rats, more axons were found in the right optic nerve than in the left optic nerve, and left-pawed rats had more axons in the left optic nerve than in the right optic nerve. CONCLUSION: The paw preference is associated with eye dominance and the number of axons in the ipsilateral optic nerve.

Right and left visual cortex areas in healthy subjects with right- and left-eye dominance.

The aim of this work was to study the differences between the right- and left-visual cortices in relation to eyedness in healthy subjects. Ocular dominance was determined by means of the near-far alignment test. To assess visual cortical areas, the right and left sagittal scenograms of cranium by magnetic resonance imaging were used. To calculate the visual cortex areas by using scenograms, Cavalieri's method was used. In the subjects with right-eye dominance, the right visual cortex was larger than the left visual cortex, and vice versa in the subjects with left-eye dominance. The right and left cuneal areas were found to be larger in males than in females. In light of these results, it was concluded that the human eyes are predominantly controlled by the ipsilateral visual cortex.

Neurodegenerative effect of electrocauterization on spinal nerve root: an experimental study.

We investigated the number of degenerated neurons in spinal roots of rabbits after spinal surgery to test if electrocauterization causes neuronal loss. The number of degenerated neurons was higher in study group than in control group, and the number of live neurons was higher in control group than in study group. These results suggest that electrocauterization applied during spinal surgery is hazardous to spinal neurons and should not be applied unless required.