638 M. Guzmán
dual effects on neural cell viability depending on signal input (e.g. agonist dose
and time of exposure), high inputs usually exerting cell growth inhibition and
death; (3) endocannabinoids and exogenous cannabinoids may possess different
pharmacological properties (e.g. agonistic potency and stability); and (4) the ori-
gin of the neural cell and its stage of differentiation may affect sensitivity to death.
Modulation of cell viability by cannabinoids is therefore a complex and still ob-
scure issue that opens exciting biological and clinical issues but requires much
further research.
Acknowledgements.
I am indebted to all my laboratory colleagues for their continuous support and for making
our research projects possible. Our work is funded by “Fundación Científica de la Asociación
Española Contra el Cáncer” and “Ministerio de Ciencia y Tecnología” (SAF2003-00745).
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