No abstract

Brain atrophy can occur several decades prior to onset of cognitive impairments. However, few longitudinal studies have examined the relationship between brain volume changes and cognition over a long follow-up period in healthy elderly women. In the present study we investigate the relationship between whole brain and hippocampal atrophy rates and longitudinal changes in cognition, including verbal episodic memory and executive function, in older women. We also examine whether baseline brain volume predicts subsequent changes in cognitive performance over a 10-year period. A total of 60 individuals from the population-based Women's Healthy Ageing Project with a mean age at baseline of 59 years underwent 3T MRI. Of these, 40 women completed follow-up cognitive assessments, 23 of whom had follow-up MRI scans. Linear regression analysis was used to examine the relationship between brain atrophy and changes in verbal episodic memory and executive function over a 10-year period. The results show that baseline measurements of frontal and temporal grey matter volumes predict changes in verbal episodic memory performance, whereas hippocampal volume at baseline is associated with changes in executive function performance over a 10-year period of follow-ups. In addition, higher whole brain and hippocampal atrophy rates are correlated with a decline in verbal episodic memory. These findings indicate that in addition to atrophy rate, smaller regional grey matter volumes even 10 years prior is associated with increased rates of cognitive decline. This study suggests useful neuroimaging biomarkers for the prediction of cognitive decline in healthy elderly women.

Using Aedes aegypti (L.) as the chief example, an account of the adult mosquito antenna, male and female, is given, and the different types of setae found thereon are described. Two of these, called types A1 and A3, are, respectively, sensilla trichoidea and sensilla basiconica; they are located chiefly at the distal end of the antenna and diminish in numbers towards its base. Type A2 setae are also sensilla trichoidea, but are smaller than type A1; they are most numerous at the base of the antenna and diminish in numbers towards the distal end. The total number of these three types is over 600 on each antenna in A. aegypti. At the tip of the antenna there are two sensilla campaniformia. Another type of seta, called A4, consisting of sensilla coeloconica, has been found so far only on the antenna of Anopheles spp. There are also two types of sensilla chaetica, making altogether seven different kinds of setae found on the mosquito antenna. Experiments with A. aegypti indicate that type A1 setae may mediate attractive odors such as that of the human hand, while type A2 setae may mediate repellent odors such as that of "612". The possible functions of the other setae are briefly considered.

Tremor in people with multiple sclerosis (MS) is a frequent and debilitating symptom with a relatively poorly understood pathophysiology. To determine the relationship between clinical tremor severity and structural magnetic resonance imaging parameters. Eleven patients with clinically definite MS and right-sided upper limb tremor were studied. Tremor severity was assessed using the Bain score (overall severity, writing, and Archimedes spiral drawing). Cerebellar dysfunction was assessed using the Scale for the Assessment and Rating of Ataxia. Dystonia was assessed using the Global Dystonia Scale adapted for upper limb. For all subjects, volume was calculated for the thalamus from T1-weighted volumetric scans using Freesurfer. Superior cerebellar peduncle (SCP) cross-sectional areas were measured manually. The presence of lesions was visually determined and the lesion volumes were calculated by the lesion growth algorithm as implemented in the Lesion Segmentation Toolbox. Right thalamic volume negatively correlated with Bain tremor severity score (ρ = − 0.65, p = 0.03). Left thalamic volume negatively correlated with general Bain tremor severity score (ρ = − 0.65, p = 0.03) and the Bain writing score (ρ = − 0.65, p = 0.03). Right SCP area negatively correlated with Bain writing score (ρ = − 0.69, p = 0.02). Finally, Bain Archimedes score was significantly higher in patients with lesions in the contralateral thalamus. Whole brain lesion load showed no relationship with tremor severity. These results implicate degeneration of key structures within the cerebello-thalamic pathway as pathological substrates for tremor in MS patients.