Morphological alterations of mitochondria may be related to metabolic and energy deficiency in neurons in Alzheimer's disease (AD) and other neurodegenerative disorders. In previous studies on the morphological and morphometric estimation of mitochondria in AD electron microscopy revealed substantial morphological and morphometric changes in the hippocampus, the acoustic cortex, the frontal cortex, and the cerebellum. This study extends this observation to subcortical centers, namely the thalamus, the globus pallidus, the red nucleus, and the locus caeruleus in 10 brains of patients who suffered from AD. The morphological alterations consisted of very obvious changes of the mitochondrial cristae, accumulation of osmiophilic material and decrease of their size, in comparison with the normal controls. Mitochondrial alterations were particularly prominent in neurons, which showed loss of dendritic spines and abbreviation of the dendritic arborization. The ultrastructural study of a large number of neurons in the thalamus and the red nucleus revealed that the mitochondrial alterations did not coexist with cytoskeletal pathology and accumulation of amyloid deposits. However, they were prominent in neurons, which demonstrated fragmentation of the cisternae of the Golgi apparatus. The morphological alterations of the mitochondria presumably suggest oxidative damage in neurons in AD brains.

Kimmerle's anomaly also known as ponticulus posticus is a common anatomical variation of the atlas, the first cervical vertebra. It is the product of the complete or incomplete ossification of the posterior atlanto-occipital membrane over the vertebral artery groove resulting in the formation of a foramen (arcuate foramen) containing the vertebral artery and the posterior branch of the C-1 spinal nerve. This variation has been associated with vertebro-basilar insufficiency symptoms, various types of headaches, and acute hearing loss. The aim of the present study is to substantiate whether Kimmerle's anomaly is the possible cause of chronic tension-type headaches and neurosensory-type hearing loss in a patient with a known history of headaches and accompanied unilateral hearing loss. The headaches demonstrated the characteristics of the chronic tension-type; the audiometric investigation concluded the hearing loss to be of the neurosensory type; whereas, the imaging examinations revealed the existence of a partial osseous bridge, that is an incomplete arcuate foramen (ponticulus posticus or Kimmerle's anomaly) on the upper surface of atlas. Both the clinical and the radiological findings of this case are indicative of a possible connection between Kimmerle's anomaly and the manifestation of chronic tension-type headaches and neurosensory-type hearing loss.

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The aim of the present study was to investigate the possible connection between interleukin-6, the acute phase (relapse) of multiple sclerosis (MS), and depression. The authors determined and statistically evaluated the levels of interleukin-6 and its soluble receptor in the serum of 28 MS patients in relapsing, 14 MS patients in remission, and 20 control subjects, as well as the presence of depression among these individuals. The results of our study indicate that depression is not only very common during relapses of MS, but also that the levels of IL-6 increase during the acute phase of the disease, especially when depression is detected.

We examined the sera of 103 demented patients of a mean age of 75 years and 60 age-matched healthy individuals, using ELISA, to investigate the levels of IgM antibodies against GM1, GD1b, and GQ1b gangliosides and their possible correlation with clinical parameters (age, severity, and type of dementia). All the individuals that demonstrated positive titers of anti-ganglioside antibodies were demented patients whereas normal controls showed borderline or negative values. Significant correlation was revealed between IgM anti-GM1 and both the age of the patients and the severity of dementia. Most of the patients with increased IgM anti-GD1b titers suffered from AD.

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Since it was first observed, synaptic plasticity has been considered as the experimental paradigm most likely to provide us with an understanding of how information is stored in the vertebrate brain. Various types have been demonstrated over these past 45 years, most notably long-term potentiation and long-term depression, and their established characteristics as well as their induction and consolidation requirements are highly indicative of this plasticity being the substrate for skills acquisition and mnemonic engraving. The molecular, biochemical, and structural models that have been proposed in the past, although most accommodate some aspect of synaptic plasticity observations, admittedly cannot offer a universally functional connection between all the phenomena that surround and result in the different modifications of synaptic efficacy. As a result, there are a number of persisting questions. In an attempt toward synthesis, we reviewed the most important studies in the field and believe that we can now propose a unifying Model for synaptic plasticity that can accommodate the experimental evidence and reconcile most of the contradictions. Moreover, from this model emerge potential answers to several unyielding questions, namely, accounting for the induction and expression of long-term depression, identifying the plasticity switch, offering a possible explanation for the sliding modification threshold, and proposing a new mechanism for synaptic tagging.

A number of biological and clinical characteristics typical of late life depression (LLD) have been suggested by recent research findings. The close association of LLD with cognitive impairment is now well documented and evidenced. However, it is still not clear whether it is depression that leads to cognitive decline, and in more severe cases, to dementia. The work presented in this review article suggests that depression and dementia frequently and strongly copresent, even if the causality remains largely opaque.