We have previously shown that impulsivity in rats is linked to decreased dopamine D 2/3 receptor availability in the ventral striatum. In the present study, we investigated, using longitudinal positron emission tomography (PET), the effects of orally administered methylphenidate (MPH), a first-line treatment for attention deficit hyperactivity disorder, on D 2/3 receptor availability in the dorsal and ventral striatum and related these changes to impulsivity. Rats were screened for impulsive behavior on a five-choice serial reaction time task. After a baseline PET scan with the D 2/3 ligand [ 18 F]fallypride, rats received 6 mg/kg MPH, orally, twice each day for 28 d. Rats were then reassessed for impulsivity and underwent a second [18 F]fallypride PET scan. Before MPH treatment, we found that D 2/3 receptor availability was significantly decreased in the left but not the right ventral striatum of high-impulse (HI) rats compared with low-impulse (LI) rats. MPH treatment increased impulsivity in LI rats, and modulated impulsivity and D 2/3 receptor availability in the dorsal and ventral striatum of HI rats through inverse relationships with baseline levels of impulsivity and D 2/3 receptor availability, respectively. However, we found no relationship between the effects of MPH on impulsivity and D 2/3 receptor availability in any of the striatal subregions investigated. These findings indicate that trait-like impulsivity is associated with decreased D 2/3 receptor availability in the left ventral striatum, and that stimulant drugs modulate impulsivity and striatal D 2/3 receptor availability through independent mechanisms.

The buccinator mucomuscular flap reliably and effectively improves velar function in the management of VPD and has low complication rates. We therefore recommend the use of the buccinator flap in primary surgical management of persisting VPD.

The aim of this study was to examine whether bioaerosols could be isolated and quantified from used car cabin filters. Car cabin filters are widely available and can provide a vast untapped resource for sampling of bioaerosols in areas with enhanced air pollution. We developed a test system where we exposed car cabin filters to birch pollen under compressed air to represent airflow onto the filter. The flow of pollen within the test system was confirmed by microscopy and realtime PCR. Testing of extraction methods was performed on the most prevalent types of filters in UK cars and confirmed it was possible to extract and quantify viable fungi, birch pollen or proteins from car filters. The main challenge of their use is envisaged to be the lack of temporal resolution as car cabin filters are not routinely changed at intervals greater than one year, however the systematic recording of the different routes driven during the sampling interval has been enabled through the common use of GPS, smartphones or similar technologies. Car filters therefore provide substantial possibilities to monitor exposure of harmful bioaerosols in the polluted traffic regions defined by the road network. This method could also be applied to studying allergen exposure associated with bioaerosols and their delivery into the human respiratory system. These findings demonstrate that car cabin filters have the potential to be used to isolate and quantify a range of bioaerosols including pollen and fungi, as well as fractions of bioaerosols, such as proteins.

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