The vertical midface lift. An improved procedure.

We describe a novel procedure for an anatomically-based face lift to correct vertical vectors in the ageing face. It has the advantage of surgical simplicity, minimal tissue removal and minimal risk. It provides an effective readjustment of cheek volume and correction of periorbital hollowness. Natural facial expression is preserved largely because there is no change in the position of the lateral canthus. The cheek is mobilised subperiosteally through a blepharoplasty incision. A second dissection is made via a short temporal incision, to join the infraorbital dissection. A Hagedorn needle is then inserted through a point inferior to the lateral canthus and in line horizontally with the nasal ala. It is passed to the orbital incision, charged with a loop of suture material, and pulled down again to the cheek incision, from where it is pushed back to the orbit to suspend the cheek. The upper border of orbicularis oculi is fixed firmly to the temporalis aponeurosis at the level of the temporal incision. We now frequently use an Endotine Midface device for fixation. Of the first 150 patients, results were excellent or good in 145. This represents a revival of the subperiosteal mask lift, and abandons the use of endoscopic techniques. In spite of its simplicity, the operation involves subperiosteal dissection as well as delicate eyelid surgery that necessitate plastic surgical skill.

The impact of restricted diet on brain function using BOLD-fMRI.

We investigated the effect of a restricted diet model on activity in the human motor cortex using functional magnetic resonance imaging (fMRI). Two series of blood oxygenation level-dependent (BOLD)-fMRI measurements were made in healthy subjects performing simple motor tasks using their right hands. The first series was done 5-10 days prior to the restricted diet schedule (controls), and the second series was performed after 25-28 days of restricted diet, in the form of a religious fast (Ramadan). The size and intensity of the activated area in the motor cortex increased during the time of restricted diet versus the controls. We conclude that restricted diet has a significant effect on cerebral activity, as shown by BOLD-fMRI, although the exact relationship between the images and neuronal activity due to the restricted diet is still to be determined.

Decreased numerical density of kainate receptor-positive neurons in the orbitofrontal cortex of chronic schizophrenics.

We utilised postmortem brain tissue to quantify sections of left and right orbitofrontal cortex (area 11) from nine schizophrenic and eight control patients from the Charing Cross Prospective Schizophrenia Study immunostained for the presence of the kainate receptor (GluR5/6/7). The numerical density of neurons immunopositive for kainate receptor was measured. Other sections from the same blocks were stained with cresyl violet to determine the total neuronal numerical density. All measurements were made blind: diagnoses were only revealed by a third party after measurements were completed. There was a significant reduction (21%) in numerical density of kainate receptor-positive neurons in both cortices in the schizophrenic group (488 cells/mm2) compared to that in the control group (618 cells/mm2) (P=0.033). Nissl-stained tissue showed no significant difference in total neuronal numerical density between control and schizophrenic groups. These observations suggest that there are actually fewer kainate receptor-positive neurons in schizophrenic orbitofrontal cortex. There was no correlation of reduced kainate receptor-positive cell number with age at death, postmortem interval, or other possibly confounding neuropathology. Our results support the concept of there being reduced glutamatergic activity in frontal cortex in schizophrenia.

The superior colliculus of the camel: a neuronal-specific nuclear protein (NeuN) and neuropeptide study.

In this study we examined the superior colliculus of the midbrain of the one-humped (dromedary) camel, Camelus dromedarius, using Nissl staining and anti-neuronal-specific nuclear protein (NeuN) immunohistochemistry for total neuronal population as well as for the enkephalins, somatostatin (SOM) and substance P (SP). It was found that, unlike in most mammals, the superior colliculus is much larger than the inferior colliculus. The superior colliculus is concerned with visual reflexes and the co-ordination of head, neck and eye movements, which are certainly of importance to this animal with large eyes, head and neck, and apparently good vision. The basic neuronal architecture and lamination of the superior colliculus are similar to that in other mammals. However, we describe for the first time an unusually large content of neurons in the superior colliculus with strong immunoreactivity for met-enkephalin, an endogenous opioid. We classified the majority of these neurons as small (perimeters of 40-50 microm), and localized diffusely throughout the superficial grey and stratum opticum. In addition, large pyramidal-like neurons with perimeters of 100 microm and above were present in the intermediate grey layer. Large unipolar cells were located immediately dorsal to the deep grey layer. By contrast, small neurons (perimeters of 40-50 microm) immunopositive to SOM and SP were located exclusively in the superficial grey layer. We propose that this system may be associated with a pain-inhibiting pathway that has been described from the periaqueductal grey matter, juxtaposing the deep layers of the superior colliculus, to the lower brainstem and spinal cord. Such pain inhibition could be important in relation to the camel's life in the harsh environment of its native deserts, often living in very high temperatures with no shade and a diet consisting largely of thorny branches.

Neuroglial response after induction of experimental allergic encephalomyelitis in susceptible and resistant rat strains.

Experimental allergic encephalomyelitis (EAE), the animal model for multiple sclerosis in humans, a T-cell mediated disease of the central nervous system is characterized by inflammatory infiltrates of myelin antigen(s)-specific T cells and consecutive demyelination. Spinal cord tissue emulsified in complete Freund's adjuvant clinical disease in the genetically susceptible Dark Agouti rats (DA) but not in Albino Oxford (AO) rats although similar inflammatory infiltrates in the CNS are observed in both strains 10-12 days after induction. We have shown that the resistance to clinical disease of AO rats is associated with rapid clearance of infiltrating mononuclear cells by a mechanism of apoptosis. Here, we demonstrate by immunohistochemical and FACS analyses of the expression of CD11b/c that microglial cells respond differently to disease induction in the two strains. Whereas microglial cells are activated throughout the period of day 10-28 days after EAE induction in AO rats they are only activated at the inception and resolution phases but not at the peak of clinical disease in DA rats when there is the highest level of CD4+ T cell infiltration. Our findings are compatible with the notion that microglia terminate effector T cells by apoptosis and that lack of this mechanism as evidenced by the lack of CD11b/c expression, support T cell survival and clinical expression of disease.

Strain gauge biomechanical evaluation of forces in orbital floor fractures.

Since the first description of orbital blow-out fractures, there has been much confusion as to their aetiology. Two principal mechanisms have been proposed to explain these fractures, the buckling and hydraulic mechanisms, caused by trauma to the orbital rim and the globe of the eye, respectively. Previous experimental and clinical studies have aimed to support one or other of these two theories. However, these studies have failed to provide quantifiable data to objectively support their conclusions. We present the results of a study of these two proposed mechanisms under identical conditions, using quantifiable intraocular pressure, variable and quantifiable force, and quantifiable bone strain distribution with strain gauge analysis in fresh intact human post-mortem cadavers. Both qualitative and quantitative findings suggest that efforts to establish one theory over the other as the primary mechanism have been misplaced. Both mechanisms produce orbital floor fractures, although these fractures differ fundamentally in their size and location. We have objectively demonstrated that it is easier to fracture the orbital floor by the hydraulic mechanism than by the buckling mechanism, and provided quantitative data for the average force required to displace the orbital floor.

Increase in HLA-DR immunoreactive microglia in frontal and temporal cortex of chronic schizophrenics.

Glia play a major role in neuronal migration, synapse formation, and control of neurotransmission in the developing and mature nervous system. This study investigated whether chronic schizophrenia is associated with glial changes in 3 regions of the cerebral cortex: dorsolateral prefrontal cortex (Brodmann's area 9), the superior temporal gyrus (area 22), and the anterior cingulate gyrus (area 24). In a blind study, astroglia and microglia were identified immunocytochemically in frozen sections from postmortem schizophrenic and control brains. Astroglia and microglia were identified using antibodies to glial fibrillary acidic protein (GFAP) and class II human leucocyte antigen (HLA-DR) respectively. They were then quantified for each cortical layer. Significant differences were found in HLA-DR+ microglial numerical density in 2 of the areas. A 28% increase (p < 0.05) was found in area 9 in 8 schizophrenics (115 +/- 9 cells/mm2) compared with 10 controls (89 +/- 5 cells/mm2), when combining all cortical layers and both cerebral hemispheres. For area 22, there was a 57% increase (p < 0.01) in microglia in 7 schizophrenics (139 +/- 6 cells/mm2) compared with 10 controls (88 +/- 5 cells/mm2). In area 24 the same trend was evident, but the results did not reach significance. Microglial number was further analyzed for each cortical layer, which confirmed the overall pattern. For all areas, numerical density of astroglia showed no significant differences between schizophrenics and controls. Cortical thickness was measured in all areas and total neuronal numerical density was estimated for area 22. Again, no significant differences were found between schizophrenics and controls. This study demonstrates a specific increase in the numerical density of HLA-DR+ microglia in temporal and frontal cortex of chronic schizophrenics, not related to aging, which might be implicated in possible changes in cortical neuropil architecture in schizophrenia.

Expression of beta-amyloid precursor and Bcl-2 proto-oncogene proteins in rat retinas after intravitreal injection of aminoadipic acid.

In order to investigate the role of glia in relation to factors that affect the expression of beta-amyloid precursor protein (betaAPP) and B cell lymphoma oncogene protein (Bcl-2) in the central nervous tissue, the patterns of expression of betaAPP and Bcl-2 in developing and mature rat retinas were studied immunocytochemically after intravitreal injection of alpha-aminoadipic acid (alpha-AAA), a glutamate analogue and gliotoxin that is known to cause injury of retinal Müller glial cells. In normal developing retinas, betaAPP and Bcl-2 were expressed primarily but transiently in a small number of neurons in the ganglion cell layer during the first postnatal week. Immunoreactivity of betaAPP and Bcl-2 appeared in the endfeet and proximal part of the radial processes of Müller glial cells from the second postnatal week onwards. In rats that received intravitreal injection of alpha-AAA at birth, there was a loss of immunoreactivity to vimentin, and a delayed expressed on betaAPP or Bcl-2 in Muller glial cells until 3-5 weeks post-injection. Immunoreactive neurons were also observed in the inner retina especially in the ganglion cell layer from 5 to 35 days after injection. A significant reduction in numerical density of cells with large somata in the ganglion cell layer was observed in the neonatally injected retinas at P56, which was accompanied by an increased immunostaining in radial processes of Müller glial cells. In contrast, no detectable changes in the expression of betaAPP and Bcl-2 were observed in retina that received alpha-AAA as adults. These results indicate that the gliotoxin alpha-AAA has long lasting effects on the expression of betaAPP and Bcl-2 in Müller glial cells as well as neurons in the developing but not mature retinas. The loss of vimentin and delayed expression of betaAPP and Bcl-2 in developing Müller glial cells suggests that the metabolic integrity of Müller cells was temporarily compromised, which may have adverse effects on developing neurons that are vulnerable or dependent on trophic support from the Müller glial cells.

Reduced dendritic spine density on cerebral cortical pyramidal neurons in schizophrenia.

OBJECTIVE: A pilot study of the density of dendritic spines on pyramidal neurons in layer III of human temporal and frontal cerebral neocortex in schizophrenia. METHODS: Postmortem material from a group of eight prospectively diagnosed schizophrenic patients, five archive schizophrenic patients, 11 non-schizophrenic controls, and one patient with schizophrenia-like psychosis, thought to be due to substance misuse, was impregnated with a rapid Golgi method. Spines were counted on the dendrites of pyramidal neurons in temporal and frontal association areas, of which the soma was in layer III (which take part in corticocortical connectivity) and which met strict criteria for impregnation quality. Altogether 25 blocks were studied in the schizophrenic group and 21 in the controls. If more than one block was examined from a single area, the counts for that area were averaged. All measurements were made blind: diagnoses were only disclosed by a third party after measurements were completed. Possible confounding affects of coexisting Alzheimer's disease were taken into account, as were the effects of age at death and postmortem interval. RESULTS: There was a significant (p<0.001) reduction in the numerical density of spines in schizophrenia (276/mm in control temporal cortex and 112/mm in schizophrenic patients, and 299 and 101 respectively in the frontal cortex). An analysis of variance, taking out effects of age at death and postmortem interval, which might have explained the low spine density for some of the schizophrenic patients, did not affect the significance of the results. CONCLUSION: The results support the concept of there being a defect in the fine structure of dendrites of pyramidal neurons, involving loss of spines, in schizophrenia and may help to explain the loss of cortical volume without loss of neurons in this condition, although the effect of neuroleptic drugs cannot be ruled out.

Complementary distributions of calbindin, parvalbumin and calretinin in the cerebellar vermis of the adult cat.

Immunocytochemistry was used to compare regional and cellular distribution of the calcium-binding proteins calbindin (CB), parvalbumin (PV) and calretinin (CR) in the cerebellar vermis of adult cats. CB and PV displayed similar patterns of distribution, mainly in Purkinje cells and their processes. Immunoreactive Purkinje cell axons were organised in bundles alternating with reaction-free strips, or raphes, of afferent fibres. In contrast, CR immunoreactivity was most apparent in unipolar brush neurons, and in mossy and climbing fibres. CR positive unipolar brush neurons were clustered and positive climbing fibres formed bands. Thus, CR was associated with afferent fibres and interneurons, and occurred in complementary structures to those demonstrated for CB and PV, mainly in efferent neurons and pathways.

Factors that affect the expression of beta-amyloid precursor protein immunoreactivity in the rat retina.

Expression of beta-amyloid precursor protein immunoreactivity in the rat retina was studied after intravitreal injection of substances known to influence neural function in different ways. The substances were the excitatory amino acid glutamate, the inflammatory agent lipopolysaccharide, the depolarizing agent potassium chloride, and the potassium channel blocker barium chloride. In comparison with controls, more beta-amyloid precursor protein immunoreactivity was observed in the radial process of Müller glial cells 24 hours after injection of glutamate or lipopolysaccharide. In contrast, administration of barium chloride greatly reduced immunostaining in Müller cells. Further, an increase in immunostaining was observed in the inner and outer plexiform layers in retinas treated with any of the 3 chemicals, and in blood vessels after injection of glutamate and lipopolysaccharide. These observations suggest that multiple but specific signaling pathways are involved in regulating expression of beta-amyloid precursor protein in distinct cell types and regions in the retina.

Differential localisation of the metabotropic glutamate receptor mGluR1a and the ionotropic glutamate receptor GluR2/3 in neurons of the human cerebral cortex.

Specimens of human cerebral cortex were obtained during neurosurgical operations and studied by immunocytochemistry and electron microscopy, using antibodies to the metabotropic glutamate receptor subunit mGluR1a and the ionotropic glutamate receptor GluR2/3. A small number of non-pyramidal neuronal cell bodies were labelled for mGluR1a. Double immunolabelling with mGluR1a and GluR2/3 showed that most pyramidal cell bodies were labelled for GluR2/3 but not for mGluR1a. Despite the non-colocalisation of these two receptor subtypes in cell bodies, however, many dendrites and dendritic spines were double-labelled for mGluR1a and GluR2/3 at electron microscopy. As there is evidence that most neurons positive for GluR2/3 are pyramidal cells, this suggests that mGluR1a is present in dendrites of pyramidal neurons, despite absent or low levels of immunoreactivity in their cell bodies.

Immunoreactivity to synaptosomal-associated protein-25 in developing rat retinas: effects of a glutamate agonist and retinal transplantation to a host brain.

In the postnatal rat retina immunoreactivity to synaptosomal-associated protein-25 (SNAP-25) was expressed primarily in the photoreceptors, inner and outer plexiform layers, and optic nerve fibres in a highly specific and age related manner. Of special interest are observations of characteristic changes of intracellular immunostaining in photoreceptors and distinct immunoreactive sublaminae in the inner plexiform layer during early postnatal stages. The overall pattern of immunoreactivity in the photoreceptor and plexiform layers remained unchanged after neonatal intravitreal injection of the glutamate agonist 2-amino-4-phosphonobutyric acid or optic tract lesion, and after adult intraorbital optic nerve section. However, a significant reduction in immunostaining in the inner plexiform and optic nerve fibre layers was observed several weeks after transplantation of the retina to a neonatal host brain. These results provide new insights into the role of SNAP-25 in membrane remodelling in relation to specific cell types and functions, and into intraretinal regulatory mechanisms that seem to be independent of the levels of glutamate and the influence of retinal ganglion cells.

A light and electron microscopic study of GAT-1-positive cells in the cerebral cortex of man and monkey.

Specimens of human cerebral cortex were obtained during neurosurgical operations and studied by immunocytochemistry and electron microscopy, using antibodies to the GABA transporter GAT-1. Cortical material from macaque monkeys was prepared similarly. Large numbers of GAT-1-positive non-pyramidal neurons were observed in layers I, II, V, and VI of the cortex. Electron microscopy also showed that the GAT-1-positive axon terminals formed symmetrical and not asymmetrical synapses, suggesting that they were the terminals of non-pyramidal neurons. Processes of cells in the walls of blood vessels were also labelled. We conclude that GAT-1 is present in cell bodies and axon terminals of non-pyramidal neurons, and a population of mural cells in blood vessels, in the primate cerebral cortex.

A light and electron microscopic study of the metabotropic glutamate receptor mGluR1a in the normal and kainate-lesioned rat hippocampus.

The distribution of the metabotropic glutamate receptor mGluR1a was studied in the normal and kainate-lesioned rat hippocampus using a monoclonal (MAb) and a polyclonal antibody to mGluR1a. Many labeled nonpyramidal neurons were observed in the stratum oriens of CA1 in sections incubated with MAb. In comparison, fewer labeled neurons were observed in this layer in sections incubated with polyclonal antibody. Many nonpyramidal neurons were observed in the stratum lucidum of CA3 and the hilus of the dentate gyrus, with both antibodies. The cell bodies of pyramidal neurons were unlabeled. A dense network of labeled processes was observed in the neuropil of the CA fields at electron microscopy. Some dendrites were very densely labeled and did not contain dendritic spines. These were identified as dendrites of nonpyramidal neurons. Other dendrites contained lightly labeled dendritic shafts, but densely labeled dendritic spines, and were identified as dendrites of pyramidal neurons. Intravenous kainate injections resulted in destruction of pyramidal neurons and a massive decrease in mGluR1a immunoreactivity in the CA fields. This decrease was obvious even at 1-5 d postinjection, when the nonpyramidal neurons in the stratum oriens remained densely labeled, suggesting that pyramidal neurons contributed significantly to mGluR1a staining in the CA fields. We conclude that the dendritic spines of hippocampal pyramidal neurons contain mGluR1a, even though little staining is observed in their parent dendritic shafts or cell bodies.

NADPH-diaphorase reactivity is reduced in the molecular layer but increased in the granular layer of primate cerebellum after prolonged anaesthesia.

To test if nitric oxide (NO) is involved in modulation of neuronal activity after global changes of brain function, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) reactivity in the cerebellar cortex was compared in monkeys maintained under anaesthesia for 24-48 h with others only anaesthetised for perfusion. After prolonged anaesthesia, NADPH-d activity was reduced in the molecular layer, but increased in the granular layer, with the maintenance of a parasagittal patchy organisation of the highly reactive granule cells. Selective labelling of NADPH-d in the infraganglionic plexuses deep to a subset of Purkinje cell somata was lost in the anaesthetised animals. This differential alteration of NADPH-d reactivity suggests that NO may play a role in regulation of neuronal and synaptic activity during anaesthesia.

Nitric oxide synthase in developing retinas and after optic tract section.

We compared the pattern of nitric oxide synthase (NOS) immunoreactivity in retinas of rats during normal development and after unilateral transection of the optic tract at postnatal day 7. NOS was first detected in the second postnatal week in the inner nuclear and inner plexiform layers. There was no detectable difference in the overall pattern of immunoreactivity between normal retinas and retinas with severe loss of ganglion cells due to the lesion. We suggest that NOS may have a role in synaptic and vascular development in the inner retina, but is unlikely to play a major role in normal physiological retinal ganglion cell death or axotomy-induced cell death.

A pivotal role for glutamate in the pathogenesis of schizophrenia, and its cognitive dysfunction.

There is mounting evidence of a glutamate dysfunction in schizophrenia, as suggested by the fact that schizophrenia and phencyclidine psychosis are similar and phencyclidine is known to block the N-methyl-D-aspartate (NMDA) subtypes of glutamate. Both occur mainly after puberty, suggesting they may share similar underlying developmental processes. Direct evidence is now accumulating from the study of messenger RNA that glutamate receptor deficiencies occur in schizophrenia and are regionally and specifically distributed. These results find support from studies of memory, electrophysiological findings, clinical treatment, and pharmacological studies in mammals and humans. Our recent findings of: a) a marked decrease in pyramidal cell dendritic spines in layer III of the frontal and temporal cortex, and b) a greater than 0.90 correlation between decrease in mRNA for the NMDA glutamate receptor and cognitive deterioration in elderly schizophrenics, present the strongest evidence to date that glutamate dysfunction plays an important role in schizophrenia.

Expression of beta-amyloid precursor protein immunoreactivity in the retina of the rat during normal development and after neonatal optic tract lesion.

Immunoreactivity to beta-amyloid precursor protein (APP) was present in the inner plexiform, ganglion cell and optic fibre layers, as well as in blood vessels, at birth in normally developing rat retinas. In the inner plexiform layer immunoreactivity disappeared by postnatal day (P) 14. A small population of ganglion cells was immunoreactive at birth, but none were visible at P7. From P14 onwards, however, there was weak immunoreactivity in ganglion cells again, and strong staining in Müller glia. Retinas affected by neonatal optic tract lesions contained more immunoreactive ganglion cells at P4 than did controls, but by P14 there was a severe loss of ganglion cells. These observations are consistent with APP being involved in retinal differentiation, including maturation of glia and neurones, synaptogenesis and possibly neuronal survival.