Convention de Londres du 21 mai 1833, suivie de la convention conclue, à Mayence, le 31 mars 1831, relativement à la navigation du Rhin

[Traité. 1833-05-21. Londres (français)]

L'art de naviguer : contenant toutes les reigles, secrets, & enseignemens necessaires à la bonne navigation ([Reprod.]) / de M. Pierre de Medina ; traduict de Castillan en François, avec augmentation & illustration de plusieurs figures et annotations par Nicolas de Nicolai,...

Collection : French books before 1601 ; 69.4

Recueil d'appareils à vapeur employés aux travaux de navigation et de chemins de fer / par A. Castor,... ; par M. Baude,...

Comprend : Rapport sur les travaux de fondation du pont du Rhin ...

Carte Phisique [sic] Administrative et Routière de la France donnant la Belgique et une partie de la Hollande : Indiquant les Relais de Poste, les Eaux Thermales et la Navigation Intérieure / par A. Beaupré

Échelle(s) : [ca 1:1 754 000], 10 Myriamètres [ = 5,7 cm]

Carte générale des Îles Britanniques contenant l'Angleterre, l'Écosse et l'Irlande : indiquant les principales routes, les canaux de navigation, les chemins de fer exécutés et en cours d'exécution dans la Grande-Bretagne / par J. Andriveau ; le burin par Piat ; écrit par Arnoul

Échelle(s) : [ca 1:1 4640 000], échelle de 25 lieues communes de France [= 7,6 cm]

Spaced training facilitates long-term retention of place navigation in adult but not in adolescent rats

Young and adult Long Evans rats were tested in the water maze according to two different procedures: half of the subjects were given one session of four trials a day for 6 days, whereas the other subjects had the same amount of training massed in 1 day. For both conditions, a 14-day retention interval was then introduced to test long-term memory. This was followed by a four-trial reversal session. All groups showed a significant learning curve, but escape latencies were shorter for the adult than for the young rats, without differential effect of the training procedure. A first probe trial (PT1) confirmed similar accurate short-term retention in all the groups. But unimpaired long-term memory was only seen in the adult rats trained with the spaced procedure. The young rats trained over 1 day also showed some retention of the platform location after 14 days, but not the other two groups. Reversal acquisition of the new platform location was rapid in the four groups. These results indicate that although accurate short-term spatial memory in the water maze is seen after a 1-day massed training in both age groups, unimpaired long-term retention is only observed in adult rats trained with 24-h inter-session intervals.

« Histoire sommaire du commerce et de la navigation des anciens, » par P.-D. HUET. (1669).

Ms. autographe, dédié à Colbert.

Absence of snapshot memory of the target view interferes with place navigation learning by rats in the water maze

Contribution of visual and nonvisual mechanisms to spatial behavior of rats in the Morris water maze was studied with a computerized infrared tracking system, which switched off the room lights when the subject entered the inner circular area of the pool with an escape platform. Naive rats trained under light-dark conditions (L-D) found the escape platform more slowly than rats trained in permanent light (L). After group members were swapped, the L-pretrained rats found under L-D conditions the same target faster and eventually approached latencies attained during L navigation. Performance of L-D-trained rats deteriorated in permanent darkness (D) but improved with continued D training. Thus L-D navigation improves gradually by procedural learning (extrapolation of the start-target azimuth into the zero-visibility zone) but remains impaired by lack of immediate visual feedback rather than by absence of the snapshot memory of the target view.

Two specific populations of GABAergic neurons originating from the medial and the caudal ganglionic eminences aid in proper navigation of callosal axons.

The corpus callosum (CC) plays a crucial role in interhemispheric communication. It has been shown that CC formation relies on the guidepost cells located in the midline region that include glutamatergic and GABAergic neurons as well as glial cells. However, the origin of these guidepost GABAergic neurons and their precise function in callosal axon pathfinding remain to be investigated. Here, we show that two distinct GABAergic neuronal subpopulations converge toward the midline prior to the arrival of callosal axons. Using in vivo and ex vivo fate mapping we show that CC GABAergic neurons originate in the caudal and medial ganglionic eminences (CGE and MGE) but not in the lateral ganglionic eminence (LGE). Time lapse imaging on organotypic slices and in vivo analyses further revealed that CC GABAergic neurons contribute to the normal navigation of callosal axons. The use of Nkx2.1 knockout (KO) mice confirmed a role of these neurons in the maintenance of proper behavior of callosal axons while growing through the CC. Indeed, using in vitro transplantation assays, we demonstrated that both MGE- and CGE-derived GABAergic neurons exert an attractive activity on callosal axons. Furthermore, by combining a sensitive RT-PCR technique with in situ hybridization, we demonstrate that CC neurons express multiple short and long range guidance cues. This study strongly suggests that MGE- and CGE-derived interneurons may guide CC axons by multiple guidance mechanisms and signaling pathways. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 647-672, 2013.