Preclinical models of Parkinson’s disease are imperative to gain insight into the neural circuits that contribute to gait dysfunction in advanced stages of the disease. The PTEN-induced putative kinase 1 (P1) knockout (KO) early onset model of Parkinson’s disease may be a useful rodent model to study the effects of neurotransmitter degeneration caused by loss of P1 function on brain activity during volitional gait. The goal of this study was to measure changes in neural activity at the cerebellar vermis (CBLv) at 8 months of age. Gait deficits, except run speed, were not significantly different from age-matched wild-type (WT) controls as previously reported. P1KO (n=4) and WT (n=4) rats were implanted with a micro-electrocorticographic array placed over CBLv lobules VI (a, b, and c) and VII. Local field potential recordings were obtained during volitional gait across a runway. Power spectral analysis and coherence analysis were used to quantify network oscillatory activity in frequency bands of interest. CBLv power was hypoactive in the beta (VIb, VIc, and VII) and alpha (VII) bands at CBLv lobules VIb, VIc, and VII in P1KO rats compared to WT controls during gait (p<0.05). These results suggest that gait improvement in P1KO rats at 8 months may be a compensatory mechanism attributed to movement corrections caused by decreased inhibition of the alpha band of CBLv lobule VII and beta band of lobules VIb, VIc, and VII. The P1KO model may be a valuable tool for understanding the circuit mechanisms underlying gait dysfunction in early-onset Parkinson’s disease patients with functional loss of P1. Future studies investigating the CBLv as a potential biomarker and therapeutic target for the treatment of gait dysfunction in Parkinson’s disease are warranted.

Parkinson’s disease is a neurodegenerative disease characterized by gait dysfunction in the advanced stages of the disease. The unilateral 6-OHDA toxin-induced model is the most studied animal model of Parkinson’s disease, which reproduces gait dysfunction after greater than 68% dopamine (DA) loss in the substantia nigra pars compacta (SNc). The extent to which the neural activity in hemi-parkinsonian rats correlates to gait dysfunction and DAergic cell loss is not clear. In this paper we report the effects of unilateral DA depletion on cerebellar vermis activity using micro-electrocorticography (μECoG) during walking and freezing on a runway. Gait and neural activity were measured in 6-OHDA lesioned and sham lesioned rats at 14d, 21d, and 28d after infusion of 6-OHDA or control vehicle into the medial forebrain bundle (MFB) (n=20). Gait deficits in 6-OHDA rats were different from sham rats at 14d (p<0.05). Gait deficits in 6-OHDA rats improved at 21d and 28d except for run speed, which decreased at 28d (p=0.018). No differences in gait deficits were observed in sham lesioned rats at any time points. Hemiparkinsonian rats showed hyperactivity in the cerebellar vermis at 21d (p<0.05), but not at 14d and 28d, and the activity was reduced during freezing epochs in lobules VIa, VIb, and VIc (p<0.05). These results suggest that DAergic cell loss causes pathological cerebellar activity at 21d postlesion and suggests that compensatory mechanisms from the intact hemisphere contribute to normalized cerebellar activity at 28d. The decrease in cerebellar oscillatory activity during freezing may be indicative of neurological changes during freezing of gait in Parkinson’s disease patients making this region a potential location for biomarker detection. Although the unilateral 6-OHDA model presents gait deficits that parallel clinical presentations of Parkinson’s disease, further studies in animal models of bilateral DA loss are needed to understand the role of the cerebellar vermis in Parkinson’s disease.

The gender gap in invention has been well studied, and the data speaks loudly, suggesting that women are under-represented in patent-intensive fields of study, especially engineering. Clearly, then, an increase in women engineering graduates might improve the probability of more women becoming patent authors. The question remains, however, "What else might we do to land more women in patent-intensive job tasks?" To answer that question, a panel discussion on this topic was held, in which the panel consisted of the authors. Discussion topics were developed and presented by the moderating professor, while women alumni provided comments and observations that were presented collectively. A summary was then prepared, and recommendations to encourage more women to write patents have been suggested.