Walkability Compass—A Space Syntax Solution for Comparative Studies

Environmental enrichment: a systematic review on the effect of a changing spatial complexity on hippocampal neurogenesis and plasticity in rodents, with considerations for translation to urban and built environments for humans

Introduction

Hippocampal neurogenesis is critical for improving learning, memory, and spatial navigation. Inhabiting and navigating spatial complexity is key to stimulating adult hippocampal neurogenesis (AHN) in rodents because they share similar hippocampal neuroplasticity characteristics with humans. AHN in humans has recently been found to persist until the tenth decade of life, but it declines with aging and is influenced by environmental enrichment. This systematic review investigated the impact of spatial complexity on neurogenesis and hippocampal plasticity in rodents, and discussed the translatability of these findings to human interventions.

Methods

Comprehensive searches were conducted on three databases in English: PubMed, Web of Science, and Scopus. All literature published until December 2023 was screened and assessed for eligibility. A total of 32 studies with original data were included, and the process is reported in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and checklist.

Results

The studies evaluated various models of spatial complexity in rodents, including environmental enrichment, changes to in-cage elements, complex layouts, and navigational mazes featuring novelty and intermittent complexity. A regression equation was formulated to synthesize key factors influencing neurogenesis, such as duration, physical activity, frequency of changes, diversity of complexity, age, living space size, and temperature.

Conclusion

Findings underscore the cognitive benefits of spatial complexity interventions and inform future translational research from rodents to humans. Home-cage enrichment and models like the Hamlet complex maze and the Marlau cage offer insight into how architectural design and urban navigational complexity can impact neurogenesis in humans. In-space changing complexity, with and without physical activity, is effective for stimulating neurogenesis. While evidence on intermittent spatial complexity in humans is limited, data from the COVID-19 pandemic lockdowns provide preliminary evidence. Existing equations relating rodent and human ages may allow for the translation of enrichment protocol durations from rodents to humans.

Developing an Objective Framework to Evaluate Street Functions

Urban street networks are a vital part of urban areas and have a remarkable influence over quality of life and the use of sustainable modes. They make up about 80% of public space and shape urban activities and identity. Therefore, it is crucial to design, develop, and maintain streets in such a way as to make the most of this large and important space in a sustainable manner. Streets have three main functions: to provide access to adjoining properties, to allow transit of users on their way from their origin to their destination, and to provide space for social activities. As such, there is a need to develop indicators, methods, and tools to evaluate how streets fulfill their functions. However, most of the previously developed frameworks rely on measuring the physical environment and transportation facilities, which reflect the potential use of streets, as opposed to their actual use. To address this gap, the main objective of this paper is to propose a holistic and objective framework to evaluate streets based on their actual use by all users. The proposed framework is developed based on direct user observation to assess the various street functions (i.e., transit, access, and place) using objective indicators at a microscopic (individual) level. The developed framework and tools build on street use evaluation by diverse disciplines such as transportation engineering, urban planning, and public health. It will help transportation agencies and urban planners to manage streets and public spaces so that they fulfill their expected functions while minimizing the negative impacts.