Related Experiment Video
Updated: Jul 10, 2026

A Comparative Approach for Quantitative Cell Counting Studies in Widely Different Mammalian Brains
Published on: January 16, 2026
Cajal and brain plasticity: insights relevant to emerging concepts of mind
1Center for Neural Science, New York University, 100 Washington Square East, New York, NY 10003, USA. eca1@nyu.edu
Abstract:
The main legacies of Cajal are his drawings of brain structure and their connections, and his ideas of brain plasticity, not only in the mature brain but also during development and after brain injury. As the 21st century begins, many scientists are asking an old question: "how does the brain express the mind?" Although most models of mind incorporate the brain connections produced by Cajal, his ideas of plasticity are largely ignored. The purpose of this chapter is to review how some of Cajal's ideas can be useful in understanding the expression of the mind. I have also introduced several concepts and facts not available during Cajal's life. I cover the concept of homeostasis, the global projections of the monoamine neurons, and the actions of "mind-expanding" drugs. The global projecting neurons, because their monoamine transmitters have such a long history, are considered 1st order systems. The point-to-point connections are considered 2nd order systems. Their importance in theories of functional localization studies is briefly reviewed. Finally, a new model is presented called "Plastic Homeostasis," which incorporates the plastic interactions between 1st and 2nd order neurons. It is hoped that this review will encourage others to study the ideas presented by Cajal when considering functions of the brain. The emerging models of the mind would be well served by a review of the theoretical writing of Cajal.
Related Concept Videos
Neuroplasticity
Plasticity
Cognitivism
Previously dominated by behaviorism, which prioritized observable behaviors and largely ignored mental processes, psychology transformed in the 1950s. Cognitive psychologists argue that understanding how we think and process information is...
Revisionist Views of Adolescent and Adult Cognition
Language and Cognition
Higher Mental Functions of Brain: Learning and Memory

