Motivational Disturbances and Effects of L-dopa Administration in Neurofibromatosis-1 Model Mice
Figure 7
The investigative rearing deficit in male Nf1 OPG mice is not rescued by L-dopa administration.
(A–C) No significant overall effects of Group were found in the third cohort of mice for ambulatory activity (A), rearing frequency (B), or time spent rearing (C) during a 30-min habituation trial in the open-field apparatus, which was conducted the day before the test session and did not include any drug/vehicle injections. (D) In contrast, planned comparisons showed that the CON+SAL mice spent significantly more time rearing to investigate the hanging object (ball) compared to the time spent rearing in the same area at the opposite end of the field (BALL vs OPP; *p = 0.017), while the Nf1 OPG+SAL group did not show significantly different rearing times with regard to the ball versus the opposite area. The Nf1 OPG+LDOPA mice reared for substantially longer times in investigating the ball versus the opposite area but these differences were not statistically significant (p = 0.064). (E) Similar results were found for the rearing frequency data where planned comparisons revealed that the CON+SAL mice spent significantly more time rearing to investigate the hanging ball versus the time spent rearing in the opposite area of the field (BALL vs OPP; *p = 0.010), while the Nf1 OPG+SAL group did not. Again, the Nf1 OPG+LDOPA mice showed a trend toward greater investigative rearing toward the ball versus the opposite area but these differences were not statistically significant (p = 0.063). (F) Although the Nf1 OPG+SAL mice tended to spend less time rearing in general throughout the field compared to the CON+SAL and Nf1 OPG+LDOPA groups, no statistically significant effects were observed for this variable. The male mice in cohort 3 were 3.5–4.5 months old and the sample size for each of the three groups was the same (n = 12).