Biology subjects

Junior, P. A. A.

Publications and source records attributed to Junior, P. A. A..

3 recordsLinked to original sources

bioRxiv2024

Advancing knowledge of West African morning glories: a taxonomic revision of Ipomoea L. (Convolvulaceae) from Ghana

Ghanas plant diversity is estimated at 2,974 plant species, belonging to 1,077 genera and 173 plant families. However, a Flora of Ghana is yet inexistent: targeted floristic and taxonomic studies are still much needed to document the plant diversity of the country fully at the family, generic and species levels. This is essential for identifying priority conservation areas in the country and support further research in crop wild relatives or medicinal plants, which will help tackle food insecurity and improve livelihoods. In this study, we provide a taxonomic revision of the Ipomoea spp. in Ghana to enhance their identification, conservation and sustainable utilization as food and medicine among other uses. An extensive literature review was carried out, including historical references and online taxonomic databases, to recover information on accepted names, type specimens and synonyms, followed by consultation of herbarium specimens at GC herbaria, to retrieve morphological information and database specimens. Specimen locality information was georeferenced, and records plotted onto distribution maps. As a result, this work provides an identification key to the species of Ipomoea of Ghana, nomenclatural information, comprehensive morphological descriptions, detailed list of examined specimens, distribution maps and notes on conservation status and traditional plant uses. In total, 28 species are fully described, 20 of which are native and eight introduced from the Americas; five are new records to Ghana.

plant biology↗

bioRxiv2021

A fully adapted headstage for electrophysiological experiments with custom and scalable electrode arrays to record widely distributed brain regions

Electrophysiological recordings lead amongst the techniques that aim to investigate the dynamics of neural activity sampled from large neural ensembles. However, the financial costs associated with the state-of-the-art technology used to manufacture probes and multi-channel recording systems make these experiments virtually inaccessible to small laboratories, especially if located in developing countries. Here, we describe a new method for implanting several tungsten electrode arrays, widely distributed over the brain. Moreover, we designed a headstage system, using the Intan(R) RHD2000 chipset, associated with a connector (replacing the expensive commercial Omnetics connector), that allows the usage of disposable and cheap cranial implants. Our results showed high-quality multichannel recording in freely moving animals (detecting local field, evoked responses and unit activities) and robust mechanical connections ensuring long-term continuous recordings. Our project represents an open source and inexpensive alternative to develop customized extracellular records from multiple brain regions.

neuroscience↗

bioRxiv2019

A Custom Microcontrolled and Wireless-Operated Chamber for Auditory Fear Conditioning

Animal behavioral paradigms, such as classical conditioning and operant conditioning, are an important tool to study the neural basis of cognition and behavior. These paradigms involve manipulating sensory stimuli in a way that learning processes are induced under controlled experimental conditions. However, the majority of the commercially available equipment did not offer flexibility to manipulate stimuli. Therefore, the development of most versatile devices would allow the study of more complex cognitive functions. The purpose of this work is to present a low-cost, customized and wireless-operated chamber for animal behavior conditioning, based on the joint operation of two microcontroller modules: Arduino Due and ESP8266-12E. Our results showed that the auditory stimulation system allows setting the carrier frequency in the range of 1 Hz up to more than 100 kHz and the sound stimulus can be modulated in amplitude, also over a wide range of frequencies. Likewise, foot-shock could be precisely manipulated regarding its amplitude (from ~200 A to ~1500 A) and frequency (up to 20 pulses per second). Finally, adult rats exposed to a protocol of cued fear conditioning in our device showed consistent behavioral response and electrophysiological evoked responses in the midbrain auditory pathway. Furthermore, the device developed in the current study represents an open source alternative to develop customized protocols to study fear memory under conditions of varied sensory stimuli.

bioengineering↗