While on the experimental point of view, reproducible lesion sizes would be optimal, on the other hand, the significant variability of lesion sizes in M1 observed in the present study is more representative of the even larger variability of cortical lesions observed in human subjects (see also a recent nonhuman primate model of motor cortex lesion, performed surgically and yielding variable lesion extent as well: Darling et al. present series of experiments, to study the efferent projections originating from PM (data will be reported elsewhere). Nevertheless, BDA was found to provide retrograde labelling as well, yielding consistent and reliable data, as seen in previous studies in which several retrograde tracers, including BDA, were switched around across cases (Rouiller et al. 1999; Tann-Garipy et al. 2002a, b; Liu et al. 2002; Morel et al. 2005; Boussaoud et al. 2005). Based on these previous data supporting the reliability of BDA for retrograde Clofilium tosylate tracing, the present analysis was conducted to assess the origin of callosal projections reaching PM. Table?1 shows a survey of the parameters of BDA injections in the premotor cortex and ibotenic acid injections to induce a permanent lesion in M1. Surgical procedures and animal care were conducted in accordance with the Guide for the Care and Use of Clofilium tosylate Laboratory Animals (ISBN 0-309-05377-3; 1996). The experimental protocol was approved first by the local (cantonal) ethical committee (surveying animal experimentation). Finally, the experiments were authorized by the cantonal (Fribourg) and federal (Swiss) veterinary officers. The present experiments were covered by the following authorizations: FR 24/95/1; FR 44/92/3; FR 157/01, FR 157/03, FR 157/04, FR 156/04, FR 156/06, FR 157e/06; FR 185-08. Table?1 Summary of the properties of each monkey included in Rabbit Polyclonal to ACHE the study hemisphere in each monkey of the location and extent of the lesion aimed at the M1 hand representation (territory) and BDA injection sites (territory in for the core of the injection site and for Clofilium tosylate the halo), as seen in transparency of the cortical surface. The actual volume of the lesions and BDA injections sites are given in Fig.?6b and Table?1. Mk-LA is not shown as it was excluded from the neuroanatomical analysis (see Table?1). b Photomicrograph of a typical BDA injection site in PMd and resulting BDA Clofilium tosylate retrogradely labelled callosal cells in the opposite hemisphere. c View of the Brinkman box used for behavioural assessment of manual dexterity, representing a variation in our modified Brinkman board task (see text). The picture shows the open facet of the box allowing access to the 20 wells, in which the pellets are placed. The picture shows that box from above with the monkeys hand aimed to a well filled with a pellet to be grasped using the precision grip between the index finger and the thumb. At the beginning of the test, the 20 wells are each filled with a pellet. As the top facet of the box is transparent, the hand movements are executed under visual control. The behavioural test was taped with a video camera placed below the box. d Raw ICMS map established post-lesion in Mk-BI, as it represented the basis to identify positions where to perform penetrations with the syringe Clofilium tosylate to infuse muscimol in PMd or PMv and then injections of BDA. Along the axes, R is for rostral and M is for medial. The represent the positions of electrodes penetrations for ICMS around the cortical surface, with to represent the body territory activated at the lowest threshold along the corresponding electrode penetration. The threshold value is given by the size of the in microAmps (see on the of the ICMS map). comprising 2 colours are for ICMS electrode penetrations along which 2 body territories were activated at comparable threshold values. The are for the sites of infusion of muscimol in PMd or in PMv, which were then used also as sites for BDA.