Which of the following viruses is/are considered to be neurotropic?

b. Herpes simplex virus

The ability to manipulate the expression of genes in the mammalian brain leads to opportunities to treat neurologic disorders. DNA viruses have been used for most attempts at gene therapy of non-malignant CNS disease. The herpes simplex type I (HSV I) has been used extensively because of its neurotropic host cell range. Recombinant HSV vectors retain functional viral genes which may be cytotoxic or may reactivate preexisting latent virus in recipient cells. To circumvent these problems, defective HSV viruses have been engineered to eliminate viral genes while retaining certain recognition sequences.