No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

In past work, we have shown neonatal quinpirole (dopamine D2/D3 agonist) treatment produces a significant increase in dopamine D2 receptor sensitivity, a phenomenon known as D2 receptor priming. Dopamine D2 receptor priming is common in psychosis. Male and female rats were administered quinpirole (1mg/kg) or saline from postnatal days 1-11 and raised to adulthood (P60). As adults, rats were administered d-amphetamine sulfate (1mg/kg) or saline every other day for 14 days. Approximately 10 min before each amphetamine or saline injection, animals were administered the D1 antagonist SCH 23390 (0.1 mg/kg), the D2 antagonist eticlopride (0.1 mg/kg) or saline. After both injections, rats were placed in a locomotor arena and activity was analyzed for a 10-min period. Results indicated that D2-priming enhanced locomotor activation effects to amphetamine in both males and females, with females demonstrating higher levels of behavioral activation. SCH 23390 blocked amphetamine sensitization in both males and females to levels below saline controls, whereas eticlopride was more effective in blocking amphetamine sensitization in males as compared to females, although eticlopride did block elevations of behavioral activation in D2-primed males and females. Seven to 10 days after sensitization, microdialysis was performed and amphetamine produced a five-fold increase in dopamine overflow in the nucleus accumbens compared to non D2-primed rats administered amphetamine. Both D1 and D2 antagonism were effective at blocking amphetamine-induced increases in dopamine overflow. These results show that neonatal quinpirole treatment enhances behavioral activation and dopamine overflow, but there appear to be sex differences in the D2 as compared to D1 response to behavioral activation produced by amphetamine.

ß arrestin-2 is a protein involved in signaling of D2 receptors and plays a mediating role in sensitization to psychostimulants and the opiate morphine. In this study, 3-4 week old BA-2 KO and wild type C57/B6 mice received nicotine tartarate (s.c, 0.5 mg/kg free base) for 7 or 14 consecutive days followed by a drug-free period. An acute nicotine challenge followed the drugfree period. Results indicated that the absence of ß-arrestin-2 reduced sensitization to nicotine in Experiment 1. BA-2 KOs eventually demonstrated sensitization in Experiment 2. However, absence of ß-arrestin-2 blocked expression of sensitization on the challenge. After the challenge, brain tissue was removed and the nucleus accumbens was dissected and analyzed for brainderived neurotrophic factor (BDNF). Results showed that BDNF positively correlated with behavioral results. These results appear to indicate the importance of the ß-arrestin-2 protein in locomotor sensitization and that dopamine signaling is related to BDNF.

The olfactory system is a great model for studying regeneration due to the olfactory epithelium’s regenerative capability which makes it a potential a source of neural stem cells. The olfactory epithelium presents three types of cells: sustentacular cells which provide support and act as glial supporting cells; olfactory sensory neurons that are in charge of detecting odorant molecules in the air; and the stem cells that generated the aforementioned cell types. Olfactory sensory neurons are constantly dying and being replaced by new neurons originating from the stem cells that lie at the base of the olfactory epithelium. We have used an injury model that allows us to remove all the olfactory sensory neurons from the olfactory epithelium, via a single injection of methimazole. Then, at different timepoints after injury we measure the functional recovery of the olfactory epithelium by analyzing the expression of specific synaptic associated markers. Specifically, we analyzed the expression of synaptophysin, tyrosine hydroxylase, vesicular glutamate transporter 1, and vesicular glutamate transporter 2. Simultaneously, we measured glomerular size in order to serve as an indicator of anatomical recovery. Finally, we correlate these findings with previously generated data in the lab associated with functional recovery through behavior.

We have examined potential influences of gender, age, and nutrition on the expression of circadian locomotor activity rhythms in the flesh fly Sarcophaga crassipalpis. We found no significant differences in endogenous circadian period under constant dark conditions resulting from gender, nutrition, or age. Male and female flesh flies were predominantly diurnal under light-dark cycles, but their entrainment patterns differed. Females displayed higher activity levels and increasing activity with age, unlike males. Moreover, females exhibited an extraordinary, but transient, departure from diurnality which we characterize as “extended dark activity” (EDA), a continuous bout of locomotor activity extending three hours, or longer, into the dark phase at twice the median of the individual’s overall locomotor activity. EDA occurred as an age-dependent response to liver consumption. Our results suggest a linkage between physiological events associated with egg provisioning and locomotor activity as well as multiple influences on the expression of circadian clock-regulated behavior.