Cognitive and anxiety-like impairments accompanied by serotonergic ultrastructural and immunohistochemical alterations in early stages of parkinsonism.

Parkinson's disease (PD) is mostly known as a dopamine deficiency syndrome due the structural and functional changes in striatal projection neurons. However, studies have considered this pathology as a multi-systemic disease in which the neurodegenerative process extends beyond the dopaminergic system. Therefore, the purpose of the present study was to investigate the morphological and immunohistochemical changes associated with behavioral and cognitive alterations in a model of parkinsonism induced by low dose of reserpine. Animals showed anxiety-like behavior and deficits in short-term recognition memory. Besides, Tyrosine Hydroxylase (TH) immunoreactive cells decreased in reserpine (RES) group in CA1 and serotonin (5-HT) immunoreactive cells decreased in RES group in CA1, CA3 and medial prefrontal cortex (mPFC). Moreover, an increase in the area (µm2) of 5 H T labeled ultrastructure (axon terminal) was observed in RES group only in CA1 and mPFC. The evidence of alterations in 5-HT immunoreactive in the premotor phase of model of parkinsonism highlights the importance of looking beyond the nigrostriatal system to elucidate the underling mechanisms and deficits in other neurotransmitters systems. This provides vital information regarding novel interventions for the management of non-motor symptoms. Additionally, the low-dose reserpine treatment has an early effect on axonal ultrastructure. As the axonopathy in PD has been increasingly recognized, the focus on axonal neurobiology is noteworthy for both neuroprotective and restorative therapeutics, and the progressive reserpine rat model can be a useful tool in this search.

System for measuring the transmission spectrum of 'in vitro' corneas.

We have developed a spectroscopy system dedicated to eye banks in order to standardize the evaluation of the donated corneas, with respect to their transparency. The system for measuring the corneal transmission spectrum basically consists of a conventional spectroscopy single beam optical apparatus, with particularities in order to attend to the needs of the eye banks, having a linear CCD (2048 sensors) as a detector. The range of evaluation of the system is from 400 to 700 nm, which is the range of interest for these kinds of sample (corneas). Dedicated software has been developed in order to acquire the data from the system and to provide the graphical interface for the user. The software is quite easy to manipulate and provides the diagnostic with respect to the transparency of the cornea, which is based on research done in association with the clinicians of the Eye Bank of Hospital das Clínicas de Ribeirão Preto (Brazil). The system presents a resolution of 9 nm (which is good enough for this kind of measurement, that presents large bandwidths) and it is in agreement with the spectra obtained from commercial spectrophotometers (the correlation factor between our system and a Beckman DU-70 is 0.995 43 for samples of well defined bandwidths, and 0.989 73 for corneas--large bandwidth).