1Higher Vocational School of Elderly Care and Occupational Therapy, Euro Academy, Pößneck, Germany, E-mail: rafael.cov@hotmail.com
2Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain, E-mail: rafael.cov@hotmail.com